Synthesis of sugars embodying conjugated carbonyl systems and related triazole derivatives from carboxymethyl glycoside lactones. Evaluation of their antimicrobial activity and toxicity

Article abstract of DOI:10.1016/j.bmc.2010.11.060

The synthesis of a series of pyranoid derivatives comprising a conjugated carbonyl function and related triazole derivatives, structurally suitable for bioactivity evaluation, was achieved in few steps starting from readily available carboxymethyl glycoside lactones (CMGL). 3-Enopyranosid-2-uloses were generated by oxidation/elimination of tri-O-acylated 2-hydroxy pyranosides. Subsequent Wittig olefination provided stereoselectively 2-C-branched-chain conjugated dienepyranosides with (E)-configuration around the exocyclic double bond. A heterogeneous CuI/Amberlyst-catalyzed 'click' chemistry protocol was used to convert glycosides bearing a propargyl moiety into the corresponding 1,2,3-triazoles. These new molecules were screened for their in vitro antibacterial and antifungal activities and those containing conjugated carbonyl systems demonstrated the best efficacy. (N-Dodecylcarbamoyl)methyl enone glycerosides were the most active ones among the enones tested. The α-anomer displayed very strong activities against Bacillus cereus and Bacillus subtilis and strong activity toward Enterococcus faecalis and the fungal pathogen Penicillium aurantiogriseum. The corresponding β-anomer presented a very strong inhibitory effect against two fungal species (Aspergillus niger and P. aurantiogriseum). (N-Dodecyl-/N-propargyl/or N-benzylcarbamoyl)methyl dienepyranosides exhibited selectively a strong activity toward E. faecalis. Further acute toxicity evaluation indicated low toxic effect of the (N-dodecylcarbamoyl)methyl enone glyceroside α-anomer and of the carbamoylmethyl dienepyranosides N-protected with propargyl or benzyl groups.

Full text of DOI:10.1016/j.bmc.2010.11.060

Bioorganic & Medicinal Chemistry 19 (2011) 926–938
Contents lists available at ScienceDirect
Bioorganic & Medicinal Chemistry
journal homepage: www.elsevier.com/locate/bmc
Synthesis of sugars embodying conjugated carbonyl systems and related
triazole derivatives from carboxymethyl glycoside lactones. Evaluation
of their antimicrobial activity and toxicity
Nuno M. Xavier a,b,c, Margarida Goulart d, Ana Neves d, Jorge Justino d, Stéphane Chambert b,c
,
b,c,
Amélia P. Rauter a, , Yves Queneau
⇑
⇑
a Universidade de Lisboa, Faculdade de Ciências, Centro de Química e Bioquímica, Departamento de Química e Bioquímica, Campo Grande, Ed. C8, Piso 5, 1749-016 Lisboa, Portugal
b INSA-Lyon, Laboratoire de Chimie Organique, Bâtiment J. Verne, 20 av A. Einstein, F—69621 Villeurbanne, France
c CNRS, UMR 5246, Institut de Chimie et Biochimie Moléculaires et Supramoléculaires, Université de Lyon, Bâtiment CPE, 43 bd du 11 novembre 1918, F—69622 Villeurbanne, France
d Escola Superior Agrária, Instituto Politécnico de Santarém, Complexo Andaluz, Apartado 279, 2001-904 Santarém, Portugal
a r t i c l e i n f o
a b s t r a c t
Article history:
The synthesis of a series of pyranoid derivatives comprising a conjugated carbonyl function and related
triazole derivatives, structurally suitable for bioactivity evaluation, was achieved in few steps starting
from readily available carboxymethyl glycoside lactones (CMGL). 3-Enopyranosid-2-uloses were gener-
ated by oxidation/elimination of tri-O-acylated 2-hydroxy pyranosides. Subsequent Wittig olefination
provided stereoselectively 2-C-branched-chain conjugated dienepyranosides with (E)-configuration
around the exocyclic double bond. A heterogeneous CuI/Amberlyst-catalyzed ‘click’ chemistry protocol
was used to convert glycosides bearing a propargyl moiety into the corresponding 1,2,3-triazoles. These
new molecules were screened for their in vitro antibacterial and antifungal activities and those contain-
ing conjugated carbonyl systems demonstrated the best efficacy. (N-Dodecylcarbamoyl)methyl enone
Received 15 October 2010
Revised 24 November 2010
Accepted 24 November 2010
Available online 2 December 2010
Keywords:
Bicyclic sugar lactones
Sugar enones
Diene pyranosides
1,2,3-Triazoles
glycerosides were the most active ones among the enones tested. The
a-anomer displayed very strong
activities against Bacillus cereus and Bacillus subtilis and strong activity toward Enterococcus faecalis and
the fungal pathogen Penicillium aurantiogriseum. The corresponding b-anomer presented a very strong
inhibitory effect against two fungal species (Aspergillus niger and P. aurantiogriseum). (N-Dodecyl-/N-
propargyl/or N-benzylcarbamoyl)methyl dienepyranosides exhibited selectively a strong activity toward
E. faecalis. Further acute toxicity evaluation indicated low toxic effect of the (N-dodecylcarbamoyl)methyl
Antimicrobial activity
enone glyceroside
or benzyl groups.
a
-anomer and of the carbamoylmethyl dienepyranosides N-protected with propargyl
Ó 2010 Elsevier Ltd. All rights reserved.
1. Introduction
fungal4 and insecticidal effects.5 These findings have motivated
the development of synthetic methodologies towards bicyclic
a
,b-Unsaturated carbonyl compounds occupy
a
prominent
fused derivatives6 and thiosugar analogues.7 Sugar enones have
also proven to be versatile building blocks for a variety of natural
products and relevant chiral molecules, such as branched-chain
sugars, C-glycosyl compounds or disaccharides.3 One of the most
well-explored enone scaffolds in terms of synthetic uses is levoglu-
cosenone, a 1,6-anhydro-3-enopyran-2-ulose, which is accessible
by pyrolysis of cellulose.8 A few examples of naturally occurring
enone-containing sugars have been reported, and those include
the fungal metabolites Microthecin,9 a 3-enopyran-2-ulose which
exhibited antibacterial and cytotoxic effects, and Ascopyrone P,10
a 1-enopyran-3-ulose known to possess antioxidant and antibacte-
rial activities.
place among various classes of molecular targets due to their broad
spectrum of biological and pharmacological activities.1 Their con-
jugated functionality, which is prompted to Michael-type addition,
may represent a receptor site for bionucleophiles, notably enzyme
sulfhydryl groups,2 and therefore makes them suitable compounds
for bioactivity screening. In particular, the incorporation of conju-
gated carbonyl functions in carbohydrates has led to useful sub-
strates for derivatization in view of their ability to undergo a
variety of transformations.3 Moreover, some of these sugar deriva-
tives have shown significant biological properties. Among them,
furanose C–C-linked
a,b-unsaturated lactones displayed anti-
A number of methods for the synthesis of pyranoid enones have
appeared in the literature,3 and some of them employ easily avail-
able glycals as starting materials. Oxidation of unprotected glycals,
for example, with PDC11 or Pd(OAc)2,12 and of their 3-O-protected
⇑
Corresponding authors. Tel.: +351 21 7500952; fax: +351 21 7500088 (A.P.R.).
E-mail addresses: aprauter@fc.ul.pt (A.P. Rauter), yves.queneau@insa-lyon.fr (Y.
Queneau).
0968-0896/$ - see front matter Ó 2010 Elsevier Ltd. All rights reserved.
doi:10.1016/j.bmc.2010.11.060

N. M. Xavier et al. / Bioorg. Med. Chem. 19 (2011) 926–938
927
derivatives, using hypervalent iodine reagents,13 leads to 1-enopy-
ran-3-uloses. Hex-3-enopyran-2-uloses comprise stereogenic cen-
ters next to the conjugated system which may induce
stereoselectivity in addition reactions. Enones of this type can be
prepared from 2-acyloxyglycal esters by simple transformations,
such as chlorination followed by elimination,14 peroxidation and
subsequent acetylation,15 or glycosylation of alcohols with these
glycal donors in the presence of a Lewis acid.16 Nevertheless, meth-
ods that involve b-acylated hexopyranosuloses as intermediates
are preferred since these compounds are prone to undergo b-elim-
ination of acyloxy groups.17 This tendency for elimination appears
to be general and has given rise either to the formation of 1-enopy-
ran-3-uloses, from easily available furan-3-uloses,7,17d or of 3-eno-
pyran-2-uloses from the corresponding acylated pyran-2-
uloses.17a–c However methodologies for the synthesis of 2-uloses,
which require partially acylated 2-hydroxy pyranosyl precursors,
are not straightforward, involving protection and deprotection
steps and low global yields. This issue can be overcome starting
from carboxymethyl glycoside lactones (CMGLs).18 The opening
of the lactone moiety of these compounds, especially by amines,
has enabled the acquisition of various pseudo glycoconjugates,
such as pseudo glycoamino acids,18a pseudo disaccharides,19 nucle-
otide sugars,19 pseudo glycolipids,20 or more recently new glycop-
robes for membranes nonlinear imaging.21 Moreover, the
connection of the sugar to another molecular block by this strategy
provides adducts containing a free and unique hydroxyl group at
position 2, available for functionalization.18c
investigate their effect in terms of antimicrobial action. The ex-
pected amides 4–10 were obtained in 66–94% yields, simply by
treatment of 1–3 with the amines in dichloromethane at room
temperature. Having a free hydroxyl group at C-2, the oxidation/
elimination of these adducts was subsequently exploited. The preli-
minary experiments were carried out with (N-propargylcarba-
moyl)methyl a-glycosides. For both a-gluco (4) and a-galacto (10)
derivatives, different oxidizing agents and conditions were used in
the search of the most appropriate method (Table 1). The system
DMSO–acetic anhydride proved to be the most effective one, giving
the desired 3-enopyranosid-2-ulose 13 in better yield (ca. 60%) and
as the single product. In its 13C NMR spectrum, the carbonyl group
was observed at d 181.7, characteristic of an
a,b-unsaturated
ketone. Diagnostic signals in the 1H NMR spectra were the olefinic
proton (H-4), observed at d 6.61 as a doublet with a coupling con-
stant J4,5 = 1.9 Hz, suggesting the adoption of an OE envelope (sofa)
conformation,17b and H-1, which was assigned at d 4.99 as a singlet.
Moreover, no significant differences in yields were obtained starting
from each of the epimers suggesting that configuration at C-4 does
not play a crucial role in the reaction outcome.
3,4,6-Tri-O-acetyl-glycopyranosid-2-uloses (11 and 12) could
be detected in the oxidation of 4/7 with PDC/Ac2O, and were the
major products when using the Dess–Martin periodinane as milder
oxidizing agent. However, isolation of the 2-ulosides was not pos-
sible by column chromatography probably due to their facile con-
version to the pyranoid enone system.
The DMSO/Ac2O procedure was thus chosen for the oxidation/
Thus, we were motivated to explore the feasibility of the oxida-
tion at C-2 of these adducts as concomitant 3,4-elimination would
be expected, giving the target 3-enopyranosid-2-uloses. Tri-O-
acylated 2-hydroxy gluco- and galactopyranosides, which differ
in the configuration at C-1, were synthesized and different oxida-
tion methods were used in order to investigate the influence of
these factors on the efficiency of the oxidation–elimination pro-
cess. Variations on the nature of the aglycon moiety also widened
the panel of compounds for subsequent biological activity evalua-
elimination of the other glycosides. Hence the a-glucosides bearing
benzylcarbamoyl (5) and dodecylcarbamoyl moieties (6) were con-
verted into the corresponding enones 14–15 in nearly quantitative
yields.
The effect of the anomeric configuration was then examined.
Performed under same conditions as those used previously, the
DMSO/Ac2O oxidation of the 2-hydroxy carbamoylmethyl b-glyco-
sides 8–10 led to b-3-enopyranosid-2-uloses 16–18, although in
lower yields (32–45%) than those obtained for their a-counterparts
tion. Branching at C-2 of the
a
-enulosides by Wittig olefination
and with some tendency to undergo decomposition. The results
obtained reflect the lower stability of the products formed, due
to the adopted EO envelope conformation, indicated by the values
of J4,5 (3.3 Hz), involving energetically unfavorable 1,3-diaxial
interactions between the substituent at C-1 and the acetoxymethyl
group.
was further accomplished leading to conjugated dienepyranosides.
(N-Propargylcarbamoyl)methyl glycosides were used for the inclu-
sion of an additional triazole motif, an heterocycle commonly re-
lated to
a variety of bioactivities, and pyranoid derivatives
comprising both the triazole and the conjugated carbonyl system
were synthesized. The structural diversity of these highly function-
alized pyranosidic derivatives allowed a rational study of their
antimicrobial activities. Compounds’ acute cytotoxicity in eukary-
otic cells was also performed. In this paper both the synthetic work
and the results of the biological assays are presented and
discussed.
2.1.2. 2-C-Branched-chain conjugated dienepyranosides
Generation of 2-C-branched-chain sugars from 3-enopyrano-
sid-2-uloses was subsequently explored. Oxidation of (N-allylcar-
bamoyl)methyl
a
-glucopyranoside 1918c with DMSO/Ac2O to
enone 20 was followed by Wittig-type treatment with the stabi-
lized ylide [(ethoxycarbonyl)methylene]triphenylphosphorane in
chloroform to provide 21 as the single product (Scheme 2). Since
no other diastereomer was obtained, which would be helpful for
comparison purposes, the (E)-configuration around the double
bond for 21 was assigned on the basis of its 1H NMR shift for
H-1, which appeared 1.3 ppm downfield from the corresponding
signal in 20, and on NOE experiments, which showed a strong
correlation between H-20 and CH3 (Ac-3) protons. This suggested
the given orientation for the ethoxycarbonyl group. Similarly,
Wittig olefination of 3-enopyranosid-2-uloses 13–15 furnished
conjugated dienepyranosides 22–24 in moderate yields (54–
61%), presenting identical 1H NMR features as those observed
for 21, in accord with the proposed (E)-configuration. While a
few examples of olefination reactions of pyranoid enones have
appeared in the literature,22 to the best of our knowledge there
2. Results and discussion
2.1. Chemistry
2.1.1. 3-Enopyranosid-2-uloses
The
procedure based on isomaltulose oxidation followed by acetyla-
tion.18a The bicyclic lactones having
-galacto (2) and b-gluco con-
figuration (3) were prepared by anomeric alkylation of glucose or
2,3,4,6-tetra-O-acetyl- -galactopyranose with tert-butyl bromo-
a-gluco CMGL 1 was synthesized following the reported
a
a-D
acetate and successive ester cleavage and cyclization.18c A series
of primary amines were then employed for the lactone ring-open-
ing of CMGLs 1–3 (Scheme 1). Propargylamine was chosen aiming
to a further derivatization of the terminal triple bond whereas
benzylamine and dodecylamine were selected for the connection
of a hydrophobic portion to the carbohydrate moiety, in order to
was only one report involving
These pyranoid ,b, ,d-unsaturated esters are not only interest-
ing for bioactivity studies but may also constitute original
a
3-enopyranoside-2-ulose.22a
a
c

928
N. M. Xavier et al. / Bioorg. Med. Chem. 19 (2011) 926–938
OAc
O
OAc
O
AcO
AcO
O
a)
AcO
AcO
c)
AcO
O
O
HO
O
O
O
O
O
NHR
NHR
C CH
AcO
13
14
15
O
4
5
6
R = CH2
R = Bn
R = CH2 C CH
R = Bn
1
R = C12H25
R = C12H25
AcO
AcO
OAc
O
OAc
O
AcO
AcO
a)
O
HO
O
O
O
NH
O
2
7
O
OAc
O
AcO
AcO
OAc
O
O
NHR
AcO
AcO
a)
O
AcO
AcO
c)
O
O
O
NHR
HO
O
O
O
3
16
17
18
8
9
R = CH2 C CH
R = Bn
R = CH2
R = Bn
C CH
10
R = C12H25
R = C12H25
OAc
O
AcO
AcO
[O]
b)
4, 7
13
O
O
O
N
H
11 α-gluco
12 α-galacto
Scheme 1. Reagents and conditions: (a) RNH2, CH2Cl2, rt, 16 h, 66–94%; (b) see Table 1; (c) DMSO/Ac2O, rt, 16 h, 96–99% (14, 15), 32–45% (16–18).
in which the triazole unit may serve as a linker between saccharide
Table 1
moieties, or a spacer entity for the generation of glycopeptide
mimics. We have applied a mild and simple catalytic procedure
consisting on the use of copper(I) iodide supported on Amberlyst
A-21 resin and dichloromethane as solvent.29 The resin is a poly-
styrene-based polymer containing a dimethylamine group which
may serve both as a chelating agent for the cooper salt and as
a base.29 The first attempted cycloaddition reactions between
the galactoside 7 and benzyl or hexenyl azide30 (Scheme 3) were
completed after overnight stirring at room temperature and
afforded the corresponding 1,2,3-triazole derivatives 25 and 26
in good isolated yields (70–74%). Similar conditions for the cou-
Results of the oxidation of (N-propargylcarbamoyl)methyl 3,4,6-tri-O-acetylglyco-
pyranosides 4 and 10
Oxidation method and conditions
Yield for 13a
4 (gluco)?13 7 (galacto)?13
DMSO/Ac2O, rt, 16 h
61
59
PDC/Ac2O, CH2Cl2, reflux, 1 h
Dess–Martin periodinane, CH2Cl2, rt, 16 h
28 (15)
6 (15)
35 (5)
6 (22)
a
Yield for the obtained 2-uloside (11 and 12) indicated in parenthesis.
templates for further synthetic elaboration through their acti-
vated diene system.
pling of the
a- and b-glucosides 4 and 8 with benzyl azide gave
successfully the expected triazoles 28 and 29. Furthermore,
‘click’ reactions that lead to 26 or 29 afforded a small amount
(4%) of a secondary product, identified by NMR and HRMS as
the 5-iodo-1,2,3-triazole derivatives 27 or 30, respectively. 5-
Iodo triazoles have already been reported as minor products in
CuI-catalyzed alkyne-azide cycloadditions when organic bases
such as NEt3 or DIPEA (diisopropylethylamine), were used. Their
formation may be due to I2 contamination in CuI, acting as
source of I+.31 The role of the base and the influence of its nature
in facilitating the formation of 5-iodo triazoles, was recently
2.1.3. Triazole derivatives
Glycosides containing alkynyl moieties were engaged in Cu(I)-
catalyzed Huisgen 1,3-dipolar cycloadditions with a terminal
azide.23 aiming at the insertion of a 1,2,3-triazole ring which is
generally recognized as one of the most biologically active motifs
among heterocyclic nucleus.24 Various examples of this so-called
‘click’ chemistry employing carbohydrates have been reported,
namely in polysaccharide modification25 or in the synthesis of car-
bohydrate macrocycles,26 oligosaccharides,27 and glycoconjugates,28
investigated and
a mechanism involving the stabilization of

N. M. Xavier et al. / Bioorg. Med. Chem. 19 (2011) 926–938
929
OAc
OAc
O
a)
O
O
H
AcO
b)
AcO
AcO
NOE
H
O
O
H
O
O
HO
O
O
O
CO2Et
N
H
O
N
H
N
H
AcO
O
19
20
21
H
H3C
c)
O
O
AcO
AcO
O
C
O
O
O
CO2Et
NHR
CH
O
NHR
AcO
AcO
22
13 R = CH2
C
CH
R = CH2
14
15
R = Bn
R = C12H25
23 R = Bn
24
R = C12H25
Scheme 2. Reagents and conditions: (a) DMSO/Ac2O, rt, 16 h; (b) Ph3P@CHCO2Et, CHCl3, 40 °C, 1.25 h, 33% overall yield; (c) Ph3P@CHCO2Et, CHCl3, 40 °C, 1–2.5 h; 54–61%.
OAc
O
R1O
R1O
OR1
O
AOc
AcO
OAc
O
AOc
AcO
a)
+
I
O
O
8
O
HO
HO
HO
9
11
3'
1'
5'
O
O
O
10
R2
N
H
N
H
N
H
N
N
N
N
7
2'
4'
6'
N
N
25 R1 = Ac, R2 = Bn
10
27
26 R1 = Ac, R2 = CH2(CH2)3CH=CH2
b)
d)
O
O
O
35 R1 = H, R2 = Bn
36 R1 = H, R2 = CH2(CH2)3CH=CH2
RO
O
O
O
N
N
N
N
31
32
R = CH2CH=CH2
R = H
OAc
O
OR
O
OAc
I
O
O
RO
RO
AcO
AcO
AcO
AcO
a)
O
O
O
+
Bn
N
H
N
O
O
HO
HO
HO
Bn
N
H
N
H
N
N
N
N
N
4
28 α-gluco, R = Ac
29
α-gluco
30
c)
β-gluco, R = Ac
7 β-gluco
d)
O
37 α-gluco, R = H
AcO
O
38
β-gluco, R = H
O
Bn
N
H
O
N
N
AcO
N
33
O
O
a)
AcO
AcO
O
O
O
O
Bn
N
N
N
N
AcO
AcO
H
CO2Et H
CO2Et
N
22
34
Scheme 3. Reagents and conditions: (a) BnN3 or N3CH2(CH2)3CH@CH2 (to give 26), CuI/Amberlyst A-21 (cat.), CH2Cl2, rt, 16 h, 71% (25), 74% (26, along with 27, 4%), 60% (28),
77% (29, along with 30, 4%), 87% (34); (b) NaH, CH2@CHCH2Br, DMF, 50 °C, 1 h, 32% (31) and 20% (32); (c) DMSO/Ac2O, rt, 16 h, 60%; (d) NEt3/H2O/MeOH, 40 °C, 16 h, 82–95%
(35–38). Aglycons’ carbon atoms numbering do not follow any nomenclature rules and were chosen to simplify the description of the NMR signals.
intermediate bis-copper complexes by the base [DMAP (4-
dimethylaminopyridine) or DMA (N,N-dimethylaniline)], allowing
a
further intermolecular delivery of iodine, was proposed.32
Although such a mechanism remains to be clarified, in our case

930
N. M. Xavier et al. / Bioorg. Med. Chem. 19 (2011) 926–938
the presence of the basic dimethylamino groups in Amberlyst A-
21 seems to be important for the iodination.
E. faecalis, while the b-anomer 18 showed virtually no activity at
all. Moreover 15 showed a very strong effect against the two spe-
cies of Bacillus tested, with zones of inhibition presenting a diam-
eter similar or greater than that of the standard antibiotic.
Moderate and good activities were displayed by 18 against B. cer-
eus and B. subtilis, respectively. The latter compound was more
This protocol proved to be convenient due to the easy separa-
tion of the catalyst from the reaction medium, simply by filtration,
and to the fully compatibility with the presence of the acetate
functionality, avoiding the addition of base and the use of an org-
ano/aqueous solvent system. To date, only one example of ‘click’
chemistry on carbohydrate templates by means of heterogeneous
catalysis was reported, in which Cu(I)-modified zeolites were
applied.33
Variations on the sugar backbone substitution were also carried
for investigating their influence on the bioactivity. The replace-
ment of the acetyl protecting groups of 26 by allyl functions was
achieved directly, along with OH-2 and N-allylation, by treatment
with sodium hydride and allyl bromide in DMF at 50 °C. The fully
allylated derivative 31 was thus obtained in 32% overall yield, to-
gether with 32, having a free OH-3 (20%).
The combination of a triazole ring with a conjugated carbonyl
system was then undertaken. Thus, oxidation of 28 by the
DMSO/Ac2O method furnished triazole-containing enuloside 33
in reasonable yield (60%). Dienepyranoside 22 was coupled
through the alkynyl residue with benzyl azide using CuI/Amberlyst
A-21 as catalyst at room temperature to generate the triazole
derivative 34 in 87% yield. No competitive cycloaddition at the
conjugated system was observed, even though such reactions be-
effective than its a-counterpart toward S. enteritidis, showing mod-
erate activity, and toward the fungal pathogen A. niger, for which a
very strong inhibitory effect was observed. In addition, both enon-
es exhibited similar activity against L. monocytogenes (moderate ef-
fect) and P. aurantiogriseum. In the latter case the activities were
found to be greater than those of the standard antibiotics.
Dienepyranosides 22–24 were shown to selectively inhibit the
growth of bacteria, namely a strong activity against E. faecalis
was detected. Compound 24 was the most active one toward S.
aureus, displaying good effect.
Although no complete correlation between bioactivity and
structure was found in these series of compounds, one obvious ef-
fect is that the bioactivity observed for the 3-enopyran-2-uloses
depends strongly on the aglycon moiety. Since enones 13 and 14,
having propargyl and benzyl moieties, did not exhibit any effect,
the long and straight chain in 15 and 18 must play a role in eliciting
the activity. The hydrophobic portion may allow these molecules
to interact with the lipid bilayer of the microorganism cell mem-
brane, or to pass through it. Once inside the lipid membrane or
in the cytoplasm, the compound may act by binding to specific tar-
gets, especially enzymes involved in key biochemical pathways for
microorganism growth. Such inhibition might arise from Michael
type addition of enzymes’ nucleophilic groups to the enone system,
despite the presence of the electrondonating group at C-3. Con-
cerning dienepyranosides 22–24, the hydrophobic nature of the
N-substituent does not seem to be a major contributor for the ob-
served bioactivity, with the exception of the effect on S. aureus, a
microbe only susceptible to compound 24.
tween azides and a,b-unsaturated esters or conjugated dienes are
known to occur, leading to triazolines34 or aziridines.35
Deprotection of the triazole-containing glycosides 25, 26, 28,
and 29 with triethylamine in methanol and water gave 35–38
(82–95%), a series of compounds bearing a hydrophilic part and a
benzyl or a hexenyl moiety as a hydrophobic substituent at posi-
tion 4 of the triazole ring.
2.2. Biological evaluation
2.2.1. Antimicrobial activity
2.2.2. Acute toxicity
The antimicrobial activities of 3-enopyranosid-2-uloses 13–15
and 18, dienepyranosides 21–24 and triazole derivatives 25–26,
28–29, 31–38 were investigated using the paper disk diffusion
method.36 Their in vitro antibacterial activity was evaluated
against Gram-negative strains such as Escherichia coli and Salmo-
nella enteritidis, and the following Gram-positive bacteria: Entero-
coccus faecalis, Listeria monocytogenes, Staphylococcus aureus,
Bacillus cereus, and Bacillus subtilis. The antifungal activity was
studied on a panel of plant pathogenic fungi which may also cause
human allergies including Aspergillus niger, Aspergillus brasiliensis,
Botrytis cinerea and Fusarium solani, the fungal plant pathogens
Penicillium aurantiogriseum, and Fusarium culmorum and the hu-
man pathogen Candida albicans. The significant results are pre-
sented in Table 2. Given the variability of the method, the results
are expressed by the average diameter of the inhibition zone de-
tected in two replicates, as well as by the symbols ꢀ, +, ++, +++,
++++, +++++, corresponding to a range of diameters, for increasing
sensitivity of the microorganism to the substance tested according
to Miyazawa et al.37 Chloramphenicol was used as control for all
bacteria tested, whereas for fungi, actidione and amphotericin B
were used.
In the search for new therapeutic agents, one of the main pre-
requisites is that the new bioactive molecules should be toxic to
the pathogen and exhibit minimal toxicities to the host cells.
Hence, our further interest was to evaluate the potential toxicity
of the new series of compounds, particularly that of the most bio-
active ones. The in vitro acute toxicity in eukaryotic cells of all mol-
ecules submitted to antimicrobial evaluation was assessed using
the MTT cell viability assay.38 The results quantified as IC50 values
are summarized in Table 3. Most of the compounds exhibited low
toxicity; the higher toxic effect was observed for the b-enuloside
18 with an IC50 value of 0.045 mg/mL, while the less toxic molecule
appeared to be the triazole-containing dienepyranoside 34 with an
IC50 value of 12 mg/mL. Among the molecules that displayed sig-
nificant antimicrobial effects, 18 and 24 (IC50 value of 0.076 mg/
mL) showed the highest toxicity. The a-enuloside 15 and dienepyr-
anosides 22 and 23 showed low toxic effect, with IC50 values of the
same order of magnitude as that of the negative control (DMSO).
3. Conclusions
Highly functionalized sugar derivatives, structurally suitable for
derivatization and for bioactivity screening, namely 3-enopyrano-
sid-2-uloses and 2-C-branched-chain dienepyranosides, were
straightforwardly accessed starting from CMGLs. Tri-O-acylated
2-hydroxy pyranosides, arising from the opening of the bicyclic
lactones, were directly converted to the target enones by oxida-
tion/elimination. The anomeric configuration influences the con-
formational stability of such enulosides and thus the yields
obtained for their preparation. A further Wittig-type olefination
Despite the presence of a triazole nucleus, which is known to
play a vital role in the efficacy of many bioactive agents, com-
pounds 25–26, 28–29, 31–38 did not show any significant antimi-
crobial activity in this screening. Pyranoid derivatives bearing
conjugated carbonyl systems were found to be the relevant bioac-
tive compounds of this set. From the 3-enopyranosid-2-uloses as-
sayed, only those carrying a dodecyl chain were active (15 and 18)
and their efficacy proved to be dependent on their anomeric
configuration. The a-enuloside 15 displayed strong activity against

N. M. Xavier et al. / Bioorg. Med. Chem. 19 (2011) 926–938
931
Table 2
Antimicrobial activities of the newly synthesized 3-enopyran-2-uloses 15, 18, and dienepyranosides 22–24
Compound
15
18
22
23
24
Controla,b
Controlc
inhibition
Ø
inhibition
Ø
inhibition
Ø
inhibition
Ø
inhibition
Ø
inhibition
Ø
inhibition
Ø
(mm)
(mm)
(mm)
(mm)
(mm)
(mm)
(mm)
Bacteriad
Salmonella
enteritidis ATCC
13076
Enterococcus
faecalis ATCC
7080
<12
24
ꢀ
14
<12
14
++
ꢀ
<12
24
ꢀ
<12
24
ꢀ
<12
22
ꢀ
41
+++++
+++++
+++++
+++++
++++
++
++++
ꢀ
++++
ꢀ
++++
ꢀ
37
33
36
Listeria
17
++
+
<12
<12
<12
<12
<12
20
monocytogenes
ATCC 19115
Staphylococcus
aureus ATCC
6538
17
++
13
ꢀ
ꢀ
+++
Bacillus cereus
ATCC 11778
Bacillus subtilis
ATCC 6633
39
40
+++++
+++++
16
21
++
<12
<12
ꢀ
ꢀ
<12
<12
ꢀ
ꢀ
<12
12
ꢀ
31
40
+++++
+++++
+++
+
Fungid
Aspergillus niger
ATCC 16404
Penicillium
aurantiogriseum
ATCC 16025
12
30
+
40
33
+++++
+++++
<12
<12
ꢀ
ꢀ
<12
12
ꢀ
<12
12
ꢀ
43
26
+++++
+++++
22
26
++++
+++++
+
+
+++++
Diameter of inhibition zones (£): +++++, £ P 26 mm; ++++, 22 mm 6 £ < 26 mm; +++, 18 mm 6 £ < 22 mm; ++, 14 mm 6 £ < 18 mm; +, 12 mm 6 £ < 14 mm; -,
£ < 12 mm.
a
Chloramphenicol for all bacteria tested with the exception of fungi for which bactidione and camphotericine B was used.
Microorganisms collection of Microbiology Laboratory from Escola Superior Agrária—Instituto Politécnico de Santarém.
d
Table 3
plausible to suppose that their mechanism of action is related to
IC50 values of in vitro acute toxicity of 3-enopyran-2-uloses 13–15 and 18,
incorporation or penetration across the cell membrane. In both
cases binding to specific receptors or enzymes may occur.
Although the electrophilicity of the enone system is reduced by
the presence of the acetoxy group at C-3, Michael acceptor ability
of enones 15, 18 could be considered to act as a second structural
requirement for bioactivity expression, particularly if enzymatic
inhibitory activity is involved. Among the dienepyranosides tested,
the contribution for the activity of the N-substituent hydrophobic-
ity was only observed for S. aureus, which was susceptible only to
24.
The results of acute toxicity indicate that from the 19 newly
synthesized compounds, only four (18, 24, 26, and 28) can be con-
sidered toxic. Compounds 15, 22, and 23, included among those
which exhibited significant antimicrobial activities, showed low
toxicity. This encourages further investigation on their use for
the control of the pathogens for which efficacy was detected.
Moreover, the low acute toxicity observed for most of the mole-
cules screened, motivates the study of their effect towards other
therapeutic targets.
dienepyranosides 21–24 and triazole derivatives 25–26, 28, 29, 32–38 in eukaryotic
cells using the MTT cell viability assay
IC50 (mg/mL)
SD
DMSO
H2O2
13
14
15
18
21
22
23
24
25
26
28
29
32
33
34
0.199
0.002
0.282
0.163
0.136
0.045
0.352
0.257
0.128
0.076
0.879
0.063
0.069
0.505
1.186
10.313
11.987
0.617
0.394
0.193
0.426
0.037
0.002
0.021
0.012
0.010
0.003
0.026
0.019
0.010
0.006
0.066
0.005
0.005
0.038
0.089
0.773
0.899
0.046
0.030
0.014
0.032
35
36
37
38
4. Experimental section
4.1. Chemistry
afforded dienepyranosides with (E)-configuration around the exo-
cyclic double bond. Conversion of (N-propargylcarbamoyl)methyl
glycosides into 1,2,3-triazole derivatives by cycloaddition with a
terminal azide was accomplished in smooth condition using a het-
erogeneous CuI/Amberlyst catalytic system.
The antimicrobial evaluation demonstrated relevant activity for
some of the synthesized enones and diene pyranosides. Only the
most hydrophobic enones, that is, those containing dodecyl chains,
were active and different antifungal and antibacterial response was
4.1.1. General methods
All reactions were monitored by TLC on Macherei-Nagel 60 F254
silica gel aluminum plates with detection under UV light (254 nm)
and/or by charring with a solution of 10% H2SO4 in EtOH. Column
chromatography was carried out on Silica Gel 60 (0.040–0.063 mm,
Macherey-Nagel). 1H and 13C NMR spectra were acquired with a
Bruker ALS 300, DRX300, (300 MHz for 1H and 75 MHz for 13C) or
DRX 400 (400 MHz for 1H and 100 MHz for 13C) spectrometer.
Chemical shifts are expressed in parts per million and are refer-
enced to solvent residual peaks. Assignments were made by COSY,
observed for
a- and b-anomers. Since the hydrophobicity appears
to be essential for the bioactivity of the synthesized enones, is

932
N. M. Xavier et al. / Bioorg. Med. Chem. 19 (2011) 926–938
HSQC, HMBC and, when necessary, by NOESY experiments. HRMS
spectra were recorded by the Centre Commun de Spectrometrie
de Masse, Université Claude Bernard Lyon 1 (Villeurbanne) using
ESI technique. Optical rotations were measured on a Perkin–Elmer
241 polarimeter at 20 °C (589 nm, sodium D line). Melting points
were determined with a Stuart Scientific SMP 3 apparatus and
are uncorrected.
(C-7), 68.1 (C-4), 61.9 (C-6), 43.0 (C-9), 20.9, 20.8, 20.7 (3 ꢂ Me,
Ac); HRMS: calcd for
476.1533.
C
21H27NO10 [M+Na]+ 476.1533, found
4.1.2.4. (N-Dodecylcarbamoyl)methyl 3,4,6-tri-O-acetyl-b-
glucopyranoside (10).
D-
Reaction of b-CMG-2-O-lactone 318c
(0.107 g, 0.31 mmol) with N-dodecylamine according to general
procedure gave the title compound (0.146 g, 89%) as a colorless
oil after purification by column chromatography (EtOAc/pentane,
4.1.2. General procedure for the opening of the CMGLs with
amines
3:2). Rf = 0.31 (EtOAc/pentane, 3:2); ½a D20
ꢁ
= ꢀ11 (c 0.7, CH2Cl2); 1H
To a solution of CMGL (0.150 g, 0.43 mmol) in anhydrous CH2Cl2
(2.5 mL) was added the amine (0.47 mmol, 1.1 equiv) and the reac-
tion mixture was stirred overnight at room temperature under
nitrogen atmosphere. After concentration under vacuum, the resi-
due was purified by column chromatography on silica gel.
NMR (400 MHz, CDCl3) d 7.04 (t, 1H, NH, J = 5.7), 5.08–4.97 (m,
2H, H-3, H-4), 4.38 (d, 1H, H-1, J1,2 = 7.9), 4.31–4.22 (m, 2H, H-6a,
H-7a, J5,6a = 5.1, J6a,6b = 12.4, J7a,7b = 15.8), 4.16 (d, part B of AB sys-
tem, 1H, H-7b), 4.07 (dd, part B of ABX system, 1H, H-6b,
J5,6b = 2.3), 3.93 (d, 1H, OH), 3.73–3.57 (m, 2H, H-2, H-5), 3.31–
3.14 (m, 2H, CH2-9), 2.07 (s, 3H, Me, Ac), 2.06 (s, 3H, Me, Ac),
2.02 (s, 3H, Me, Ac), 1.54–1.41 (m, 2H, CH2-10), 1.32–1.19 (m, 18
H, C9H18), 0.86 (t, 3H, CH3-20, J = 6.6); 13C NMR (100 MHz, CDCl3)
d 171.4, 170.7, 169.7, 169.2 (3 ꢂ CO-Ac, CO-8), 103.3 (C-1), 75.5
(C-3), 72.2, 72.2 (C-2, C-5), 69.1 (C-7), 68.0 (C-4), 62.0 (C-6), 39.3
(C-9), 32.0, 29.7, 29.7, 29.5, 29.4, 29.4, 27.0, 22.8 (C-10–C-19),
20.9, 20.8, 20.7 (2 ꢂ Me, Ac), 14.2 (CH3-20); HRMS: calcd for
C26H45NO10 [M+Na]+ 554.2941, found 554.2940.
4.1.2.1. (N-Benzylcarbamoyl)methyl 3,4,6-tri-O-acetyl-
a-D-gluco-
pyranoside (5). Reaction of
a
-CMG lactone 118a (0.10 g,
0.29 mmol) with benzylamine according to general procedure gave
the title compound (87 mg, 66%) as a colorless oil after purification
by column chromatography (from EtOAc/pentane, 3:2 to EtOAc);
Rf = 0.21 (EtOAc/pentane, 1:1). ½a D20
ꢁ
= +60 (c 0.8, CH2Cl2); 1H NMR
(400 MHz, CDCl3) d 7.88 (t, 1H, NH, J = 5.8), 7.27–7.12 (m, 5H,
Ph), 5.18 (t, 1H, H-3, J2,3 = J3,4 = 9.8), 4.90 (t, 1H, H-4, J3,4 = J4,5),
4.79 (d, 1H, H-1, J1,2 = 3.8), 4.33–4.23 (m, 3H, CH2-9, OH), 4.18
(dd, part A of ABX system, H-6a, J5,6a = 4.5, J6a,6b = 12.3), 4.10–
3.87 (m, 4H, H-5, H-6b, CH2-7, J7a,7b = 15.6), 3.70–3.61 (m, 1H, H-
2), 1.99 (s, 3H, Me, Ac), 1.94 (s, 6H, 2 ꢂ Me, Ac); 13C NMR
(100 MHz, CDCl3) d 171.7, 170.7, 169.6, 169.3 (3 ꢂ CO-Ac, CO-8),
137.9 (Cq, Ph), 128.6, 127.5, 127.4 (CH, Ph), 99.3 (C-1), 73.3 (C-3),
70.2 (C-2), 68.1, 68.0, 67.4 (C-4, C-5, C-7), 61.9 (C-6), 42.8 (C-9),
4.1.3. General procedure for PDC/Ac2O oxidation of 4, 7
A
solution of 3,4,6-tri-O-acetylglycopyranoside (0.1 g,
0.25 mmol) in dry CH2Cl2 (0.7 mL) was added to a mixture of
PDC (70 mg, 0.19 mmol) and Ac2O (0.07 mL, 0.8 mmol) in dry
CH2Cl2 (1.5 mL) under nitrogen atmosphere The resulting mixture
was stirred under reflux for 1 h, then cooled to rt. The solvent was
removed in vacuo. The gummy residue was triturated with ethyl
acetate (15 mL) and the mixture was filtered through a short pad
of Florisil. After evaporation of the solvent, the crude was purified
by column chromatography (EtOAc/pentane, 3:2).
20.8, 20.7, 20.6 (3 ꢂ Me, Ac); HRMS: calcd for
C21H27NO10
[M+Na]+ 476.1533, found 476.1535.
4.1.2.2. (N-Propargylcarbamoyl)methyl 3,4,6-tri-O-acetyl-b-
glucopyranoside (8).
D-
Reaction of b-CMG lactone 318c
4.1.4. General procedure for Dess–Martin oxidation of 4, 7
To a solution of 3,4,6-tri-O-acetylglycopyranoside (0.3 mmol) in
dry CH2Cl2 (6 mL) was added Dess–Martin periodinane (0.165 g,
0.39 mmol), and the reaction mixture was stirred overnight at
room temperature under nitrogen atmosphere. A saturated NaH-
CO3 solution was added, and the aqueous phase was extracted
twice with dichloromethane. The combined organic layers were
washed with water and dried with Na2SO4. After filtration and
evaporation of the solvent, the residue was purified by column
chromatography (EtOAc/pentane, 3:2).
(0.11 g, 0.32 mmol) with N-propargylamine according to general
procedure gave the title compound (0.11, 86%) as a pale oil after
purification by column chromatography (from EtOAc/pentane,
3:2 to 4:1). Rf = 0.35 (EtOAc/pentane, 4:1);
½
a 2D0
ꢁ
= ꢀ3 (c 0.4,
CH2Cl2); 1H NMR (400 MHz, CDCl3) d 5.09–5.01 (m, 2H, H-3, H-
4), 4.41 (d, 1H, H-1, J1,2 = 7.9), 4.37–4.21 (m, 3H, H-6a, CH2-7,
J5,6a = 5.1, J6a,6b = 12.4, J7a,7b = 16.1), 4.15–4.06 (m, 3H, H-6b, CH2-
9), 3.74–3.62 (m, 2H, H-2, H-5), 2.23 (t, 1H, H-11, J = 2.6), 2.11 (s,
3H, Me, Ac), 2.09 (s, 3H, Me, Ac), 2.04 (s, 3H, Me, Ac); 13C NMR
(100 MHz, CDCl3) d 171.7, 170.8, 169.7, 169.0 (3 ꢂ CO-Ac, CO-8),
103.4 (C-1), 79.2 (C-10),75.6 (C-3), 72.4, 72.3 (C-2, C-5), 71.8 (C-
11), 69.4 (C-7), 67.9 (C-4), 62.0 (C-6), 28.8 (C-9), 21.0, 20.9, 20.8
(3 ꢂ Me, Ac); HRMS: calcd for C17H23NO10 [M+Na]+ 424.1220,
found 424.1219.
4.1.4.1. (N-Propargylcarbamoyl)methyl 3,4,6-tri-O-acetyl-
arabino-hexopyranosid-2-ulose (11).
a-D-
Oxidation of 418a with
PDC/Ac2O (0.1 g, 0.25 mmol of 4) or with Dess–Martin periodinane
(0.12 g, 0.3 mmol of 4), according to general procedures, afforded
11 (15 mg and 18 mg, respectively, 15% yield in both cases), insep-
arably contaminated with compound 13. Rf = 0.22 (EtOAc/pentane,
1:1); 1H NMR (300 MHz, CDCl3) d 5.53 (d, 1H, H-3, J3,4 = 9.6), 5.20
(t, 1H, H-4, J3,4 ꢃ J4,5), 5.38, 4.91 (s, 1H, H-1), 4.54 -4.49 (d, part A
of AB system, H-7a, J7a,7b = 16.9), 4.38 (d, part B of AB system part,
H-7b), 4.34–4.25 (m, 3H, H-5, H-6a, H-9a) 4.16–4.10 (m, 2H, H-6b,
H-9b), 2.15 (t, 1H, H-11, J = 2.5), 2.12 (s, 3H, Me, Ac), 2.08 (m, 3H,
Me, Ac), 2.08 (s, 3H, Me, Ac); 13C NMR (75 MHz, CDCl3) d 170.9,
170.1, 169.9, 165.7 (2 ꢂ CO-Ac, CO-8), 97.5 (C-1), 79.5 (C-10),
75.0 (C-3), 70.7 (C-5), 70.4 (C-11), 67.6 (C-4), 66.8 (C-7), 62.2 (C-
6), 30.5 (C-9), 21.5, 20.9, 20.8 (3 ꢂ Me, Ac); LRMS (ESI) m/
z = 422.1 [M+Na]+, 438.0 [M+K]+, 820.6 [M2Na]+.
4.1.2.3. (N-Benzylcarbamoyl)methyl 3,4,6-tri-O-acetyl-b-
pyranoside (9).
D-gluco-
Reaction of b-CMG lactone 318c (0.15 g,
0.43 mmol) with N-benzylamine according to general procedure
gave the title compound (0.185 g, 94%) as a colorless oil after purifi-
cation by column chromatography (EtOAc/pentane, 3:2 to 4:1).
Rf = 0.38 (EtOAc/pentane, 4:1); ½a D20
ꢁ
= ꢀ6 (c 0.9, CH2Cl2); 1H NMR
(400 MHz, CDCl3) d 7.40 (t, 1H, NH), 7.29–7.15 (m, 5H, Ph), 5.06–
4.93 (m, 2H, H-3, H-4, J2,3 = J3,4 = J4,5 = 9.3), 4.48 (dd, part A of ABX
system, 1H, H-9a, J9a,NH = 6.0, Ja,b = 14.9), 4.40–4.15 (m, 5H, H-1, H-
9b, H-6a, CH2-7, J1,2 = 7.8, J5,6a = 4.8, J6a,6b = 12.6, J7a,7b = 15.9,
J9b,NH = 5.8), 4.03 (dd, part B of ABX system, H-6b, J5,6b = 2.0), 3.64
(ddd, 1H, H-5), 3.57 (dd, 1H, H-2), 2.04 (s, 3H, Me, Ac), 2.03 (s, 3H,
Me, Ac), 2.01 (s, 3H, Me, Ac); 13C NMR (100 MHz, CDCl3) d 171.2,
170.7, 169.7, 169.3 (3 ꢂ CO-Ac, CO-8), 137.9 (Cq, Ph), 128.8, 127.7,
127.6 (CH, Ph), 103.4 (C-1), 75.2 (C-3), 72.1, 72.0 (C-2, C-5), 69.2
4.1.4.2. (N-Propargylcarbamoyl)methyl 3,4,6-tri-O-acetyl-
lyxo-hexopyranosid-2-ulose (12).
Oxidation of 718b with
PDC/Ac2O or with Dess–Martin periodinane according to general
a-D-

N. M. Xavier et al. / Bioorg. Med. Chem. 19 (2011) 926–938
933
procedures, afforded 12 in 5% yield (5 mg, starting from 0.1 g of 7),
and in 22% yield (23 mg, starting from 0.105 g of 10), respectively,
inseparably contaminated with compound 13. Rf = 0.22 (EtOAc/
pentane, 1:1); 1H NMR (300 MHz, CDCl3) d 5.50 (dd, 1H, H-4,
J3,4 = 3.5, J4,5 = 1.5), 5.38 (d, 1H, H-3), 4.91 (s, 1H, H-1), 4.56–4.49
(m, 2H, H-5, H-7a, J7a,7b = 16.9), 4.38 (d, part B of AB system part,
H-7b), 4.29 (dd, part A of ABX system, 1H, H-9a, J9a,H-11 = 2.0,
J9a,9b = 16.9), 4.26–4.09 (m, 3H, CH2-6, H-9b, J5,6a = 6.0, J5,6b = 7.1,
J6a,6b = 11.6), 2.21 (s, 3H, Me, Ac), 2.14–2.10 (m, 4H, H-11,Me, Ac),
2.06 (s, 3H, Me, Ac); 13C NMR (75 MHz, CDCl3) d 170.5, 169.5,
169.1, 165.3 (2 ꢂ CO-Ac, CO-8), 98.7 (C-1), 80.7 (C-10), 71.3 (C-3),
70.2 (C-11), 68.6 (C-5), 67.5 (C-4), 66.8 (C-7), 61.3 (C-6), 30.8 (C-
9), 21.3, 20.8, 20.8 (3 ꢂ Me, Ac); HRMS: calcd for C17H21NO10
[M+Na]+ 422.1063, found 422.1059.
(0.105 g, 99%) as a yellow oil after purification by column chroma-
tography (EtOAc/pentane, 1:1). Rf = 0.25 (EtOAc/pentane, 2:3);
½
a 2D0 = +30 (c 1, CH2Cl2); 1H NMR (300 MHz, CDCl3) d 6.65 (d, 1H,
H-4, J4,5 = 1.9), 6.49 (t, 1H, NH), 5.02 (s, 1H, H-1), 4.95 (td, 1H, H-
ꢁ
5), 4.42 (dd, part of ABX system, 1H, H-6a, J5,6a = 5.5,
A
J6a,6b = 11.8), 4.31–4.21 (m, 2H, H-6b, H-7a, J5,6b = 4.5,
J7a,7b = 15.1), 4.15 (d, part B of AB system, 1H, H-7b), 3.33–3.18
(m, 2H, CH2-9), 2.26 (s, 3H, Me, Ac), 2.10 (s, 3H, Me, Ac), 1.55–
1.45 (m, 2H, CH2-10), 1.33–1.20 (m, 18 H, C9H18), 0.86 (t, 3H,
CH3-20, J = 7.1); 13C NMR (75 MHz, CDCl3) d 181.9 (CO-2), 170.7,
167.9, 167.8 (2 ꢂ CO-Ac, CO-8), 142.0 (C-3), 133.2 (C-4), 98.2 (C-
1), 68.3 (C-5, C-7), 64.4 (C-6), 39.3 (C-9), 32.0, 29.8, 29.7, 29.6,
29.5 29.4, 29.4, 27.0, 22.8 (C-10–C19), 20.8, 20.4 (2 ꢂ Me, Ac),
14.2 (CH3-20); HRMS: calcd for C24H39NO8 [M+Na]+ 492.2573,
found 492.2574.
4.1.5. General procedure for DMSO/Ac2O oxidation
To a solutionof 3,4,6-tri-O-acetylglycopyranoside (0.38 mmol) in
anhydrous DMSO (25 mL) was added acetic anhydride (12.5 mL).
The mixture was stirred at room temperature overnight under nitro-
gen atmosphere. Water (50 mL) was added and the resulting mix-
ture was extracted with EtOAc (3 ꢂ 25 mL). The combined organic
layers were washed with water and brine and dried with Na2SO4.
After filtration, the solvent was removed under vacuum and the
crude was purified by column chromatography on silica gel.
4.1.5.4. (N-Propargylcarbamoyl)methyl 3,6-di-O-acetyl-4-deoxy-
b-D-glycero-hex-3-enopyranosid-2-ulose (16).
DMSO/Ac2O
oxidation of compound 8 (0.1 g, 0.25 mmol) according to general
procedure gave the corresponding 3-enopyranosid-2-ulose 16
(27 mg, 32%) as a colorless oil after purification by column chroma-
tography (EtOAc/pentane, 3:2). Rf = 0.48 (EtOAc/pentane, 4:1); 1H
NMR (300 MHz, CDCl3) d 7.00 (t, 1H, NH), 6.70 (d, 1H, H-4,
J4,5 = 3.0), 5.07 (s, 1H, H-1), 4.95–4.89 (ddd, 1H, H-5), 4.47–4.25
(m, 3H, H-6a, H-6b, H-7a, J5,6a = 6.6, J5,6b = 4.9, J6a,6b = 11.7,
J7a,7b = 15.7), 4.21 (d, part B of AB system, 1H, H-7b), 4.12–4.06
(m, 2H, CH2-9), 2.27 (s, 3H, Me, Ac), 2.23 (t, 1H, H-11, J = 2.6),
4.1.5.1. (N-Propargylcarbamoyl)methyl 3,6-di-O-acetyl-4-deoxy-
a
-
D
-glycero-hex-3-enopyranosid-2-ulose (13).
DMSO/Ac2O
oxidation of compound 418a (0. 123 g, 0.31 mmol) or 7 (0. 15 g,
0.37 mmol) according to general procedure gave the corresponding
3-enopyranosid-2-ulose 13 (63 mg, 61% and 74 mg, 59%, respec-
tively) as a colorless oil after purification by column chromatogra-
2.12 (s, 3H, Me, Ac); HRMS: calcd for
362.0852, found 362.0852.
C
15H17NO8 [M+Na]+
4.1.5.5. (N-Benzylcarbamoyl)methyl 3,6-di-O-acetyl-4-deoxy-b-
D-glycero-hex-3-enopyranosid-2-ulose (17). DMSO/Ac2O
phy (EtOAc/pentane, 1:1). Rf = 0.31 (EtOAc/pentane, 1:1); ½a D20
ꢁ
= +7
(c 0.9, CH2Cl2); 1H NMR (300 MHz, CDCl3) d 6.77 (t, 1H, NH), 6.65
(d, 1H, H-4, J4,5 = 1.9), 5.07 (s, 1H, H-1), 4.95 (td, 1H, H-5), 4.42
(dd, part A of ABX system, 1H, H-6a, J5,6a = 5.3, J6a,6b = 11.7), 4.31
(d, part A of AB system, 1H, H-7a, J7a,7b = 15.3), 4.22 (dd, part B of
ABX system, 1H, H-6b, J5,6b = 4.5), 4.16 (d, part B of AB system,
1H, H-7b), 4.09–4.02 (m, 2H, CH2-9), 2.24 (s, 3H, Me, Ac), 2.23 (t,
1H, H-11, J = 2.6), 2.08 (s, 3H, Me, Ac); 13C NMR (75 MHz, CDCl3)
d 181.7 (CO-2), 170.7, 168.0, 167.8 (2 ꢂ CO-Ac, CO-8), 141.9 (C-3),
133.3 (C-4), 98.1 (C-1), 79.1 (C-10), 71.8 (C-11), 68.4, 68.3 (C-5,
C-7), 64.3 (C-6), 28.8 (C-9), 20.8, 20.4 (2 ꢂ Me, Ac); HRMS: calcd
for C15H17NO8 [M+Na]+ 362.0852, found 362.0851.
oxidation of compound 9 (0.11 g, 0.24 mmol) according to general
procedure gave the corresponding 3-enopyranosid-2-ulose 17
(42 mg, 45%) as a colorless oil after purification by column chroma-
tography (from EtOAc/pentane, 3:2 to 4:1); Rf = 0.49 (EtOAc/pen-
tane, 4:1); 1H NMR (400 MHz, CDCl3) d 7.36–7.24 (m, 5H, Ph),
7.13 (br t, 1H, NH), 6.67 (d, 1H, H-4, J4,5 = 3.0), 5.05 (s, 1H, H-1),
4.89 (ddd, 1H, H-5), 4.53–4.33 (m, 4H, H-6a, H-7a, CH2-9,
J7a,7b = 15.4, J9,NH = 5.8, J9a,9b = 9.2), 4.32–4.18 (m, 2H, H-6b, H-7b,
J5,6b = 5.1, J6a,6b = 11.7), 2.24 (s, 3H, Me, Ac), 2.08 (s, 3H, Me, Ac);
HRMS: calcd for C19H21NO8 [M+Na]+ 414.1165, found 414.1165.
4.1.5.6. (N-Dodecylcarbamoyl)methyl 3,6-di-O-acetyl-4-deoxy-
4.1.5.2. (N-Benzylcarbamoyl)methyl 3,6-di-O-acetyl-4-deoxy-
a-
b-D
-glycero-hex-3-enopyranosid-2-ulose (18).
DMSO/Ac2O
D
-glycero-hex-3-enopyranosid-2-ulose (14). DMSO/Ac2O
oxidation of compound 10 (0.1 g, 0.19 mmol) according to general
procedure gave the corresponding 3-enopyranosid-2-ulose 18
(33 mg, 37%) as a colorless oil after purification by column chroma-
tography (from EtOAc/pentane, 3:2 to 4:1). Rf = 0.43 (EtOAc/pen-
tane, 3:2); 1H NMR (300 MHz, CDCl3) d 6.74 (t, 1H, NH), 6.69 (d,
1H, H-4, J4,5 = 3.2), 5.03 (s, 1H, H-1), 4.94–4.87 (m, 1H, H-5),
4.43–4.26 (m, 3H, H-6a, H-6b, H-7a, J5,6a = 6.8, J5,6b = 5.1,
J6a,6b = 11.5, J7a,7b = 15.5), 3.31–3.22 (m, 2H, CH2-9), 2.26 (s, 3H,
Me, Ac), 2.11 (s, 3H, Me, Ac), 1.57–1.44 (m, 2H, CH2-10), 1.33–
1.21 (m, 18 H, C9H18), 0.87 (t, 3H, CH3-20, J = 6.8); 13C NMR
(75 MHz, CDCl3) d 182.5 (CO-2), 170.6, 168.3, 168.0 (2 ꢂ CO-Ac,
CO-8), 142.4 (C-3), 133.1 (C-4), 99.1 (C-1), 71.2, 68.7 (C-5, C-7),
65.2 (C-6), 39.3 (C-9), 32.0, 29.8, 29.7, 29.6, 29.5, 29.4, 27.0, 22.8
(C-10–C19), 20.8, 20.4 (2 ꢂ Me, Ac), 14.2 (CH3-20); HRMS: calcd
for C24H39NO8 [M+Na]+ 492.2573, found 492.2574.
oxidation of compound 5 (80 mg, 0.18 mmol) according to general
procedure gave the corresponding 3-enopyranosid-2-ulose 14
(66 mg, 96%) as a colorless oil after purification by column chroma-
tography (EtOAc/pentane, 3:2). Rf = 0.31 (EtOAc/pentane, 1:1);
½
a 2D0 = +13 (c 0.7, CH2Cl2); 1H NMR (400 MHz, CDCl3) d 7.36–7.24
ꢁ
(m, 5H, Ph), 6.86 (br t, 1H, NH), 6.62 (d, 1H, H-4, J4,5 = 1.9), 5.04 (s,
1H, H-1), 4.93 (td, 1H, H-5), 4.51–4.32 (m, 4H, H-6a, H-7a, CH2-9,
J5,6a = 5.3, J6a,6b = 11.9, J7a,7b = 15.6), 4.26–4.18 (m, 2H, H-6b, H-7b,
J5,6b = 4.5), 2.24 (s, 3H, Me, Ac), 2.10 (s, 3H, Me, Ac); 13C NMR
(100 MHz, CDCl3) d 181.8 (CO-2), 170.7, 168.0, 167.9 (2 ꢂ CO-Ac,
CO-8), 141.9 (C-3), 137.9 (Cq, Ph), 133.2 (C-4), 128.8, 127.9, 127.7
(CH, Ph), 98.2 (C-1), 68.3 (C-5, C-7), 64.4 (C-6), 99.3 (C-1), 73.3 (C-
3), 70.2 (C-2), 68.4 (C-5, C-7), 64.3 (C-6), 43.1 (C-9), 20.8, 20.4
(2 ꢂ Me, Ac); HRMS: calcd for C19H21NO8 [M+Na]+ 414.1165, found
414.1167.
4.1.6. General procedure for Wittig olefination of 3-enopyranosid-
2-uloses
4.1.5.3. (N-Dodecylcarbamoyl)methyl 3,6-di-O-acetyl-4-deoxy-
a
-
D
-glycero-hex-3-enopyranosid-2-ulose (15).
DMSO/Ac2O
To a solution of 3-enopyranosid-2-ulose (0.10 mmol) in CHCl3
(1 mL) was added [(ethoxycarbonyl)methylene]triphenylphospho-
rane (45 mg, 0.13 mmol). The whole solution was stirred at 40 °C
oxidation of compound 618a (0.12 g, 0.23 mmol) according to gen-
eral procedure gave the corresponding 3-enopyranosid-2-ulose 15

934
N. M. Xavier et al. / Bioorg. Med. Chem. 19 (2011) 926–938
until complete conversion, as indicated by TLC. The solvent was re-
moved under vacuum and the residue was purified by column
chromatography on silica gel.
sid-2-ulose 14 (40 mg, 0.1 mmol) according to general procedure,
was completed within 2 h. The title compound was obtained as a
white solid (29 mg, 61%) after purification by column chromatog-
raphy (diethyl ether/hexane, 7:3 to diethyl ether). Rf = 0.23
4.1.6.1. (N-Allylcarbamoyl)methyl 3,6-di-O-acetyl-4-deoxy-
a
-D
-
(EtOAc/pentane, 2:3); mp 123–125 °C; ½a D20
ꢁ
= +27 (c 0.3, CH2Cl2);
glycero-hex-3-enopyranosid-2-ulose (20) and (N-Allylcarba-
moyl)methyl 3,6-di-O-acetyl-2,4-dideoxy-2-C-[(E)-(ethoxycar-
1H NMR (400 MHz, CDCl3) d 7.52 (t, 1H, NH), 7.32–7.28 (m, 3H,
Ph), 7.27–7.25 (m, 2H, Ph), 6.38 (s, 1H, H-1), 5.93 (dd, 1H, H-4,
J2 ,4 = 1.0, J4,5 = 2.3), 5.86 (br d, 1H, H-20), 4.70 (ddd, 1H, H-5), 4.54
0
bonyl)methylene]-
(21).
a
-
D
-glycero-hex-3-enopyranoside
DMSO/Ac2O oxidation of compound 1918c (75 mg,
(dd, part A of ABX system, H-9a, J9a,NH = 6.0, J9a,9b = 14.9), 4.46
(dd, part B of ABX system, H-9b, J9b,NH = 5.8), 4.41–4.32 (m, 2H,
H-6a, H-7a, J5,6a = 5.8, J6a,6b = 11.6, J7a,7b = 15.6), 4.29 (d, part B of
0.19 mmol) to 3-enopyranosid-2-ulose 20 was performed accord-
ing to general procedure. After column chromatography (EtOAc/
pentane, 3:2), 20 was subjected to Wittig olefination which was
completed within 1.25 h. Purification by column chromatography
(from Et2O/hexane, 9:1 to Et2O) afforded 21 (25 mg, 33% overall
yield), as white solid.
AB system, H-7a), 4.16 (dd, part
B of ABX system, H-6b,
J5,6b = 4.0), 4.10–3.97 (m, 2H, CH2-Et), 2.24 (s, 3H, Me, Ac), 2.10
(s, 3H, Me, Ac), 1.21 (t, 1H, CH3-Et, J = 7.1); 13C NMR (100 MHz,
CDCl3) d 170.9, 169.0, 168.0 (2 ꢂ CO-Ac, CO-8), 165.4 (CO), 142.1,
140.3 (C-2, C-3), 138.3 (Cq, Ph), 128.6, 128.0, 127.4 (CH, Ph),
121.4 (C-4), 114.3 (C-20), 94.3 (C-1), 67.1, 66.6 (C-5, C-7), 64.9 (C-
6), 61.2 (CH2-Et), 43.1 (C-9), 20.9, 20.9 (2 ꢂ Me, Ac), 14.2 (CH3-
Et); HRMS: calcd for C23H27NO9 [M+Na]+ 484.1584, found
484.1591.
Data for 20: Rf = 0.42 (EtOAc/pentane, 3:2); 1H NMR (300 MHz,
CDCl3) d 6.65 (d, 1H, H-4, J4,5 = 1.9), 6.61 (br t, 1H, NH), 5.91–5.74
(m, 1H, H-10), 5.24–5.01 (m, 2H, CH2-11), 5.04 (s, 1H, H-1), 4.96
(td, 1H, H-5), 4.42 (dd, part A of ABX system, 1H, H-6a, J5,6a = 5.3,
J6a,6b = 11.7), 4.32 (d, part A of AB system, 1H, H-7a, J7a,7b = 15.3),
4.23 (dd, part B of ABX system, 1H, H-6b, J5,6a = 4.7), 4.18 (d, part
B of AB system 1H, H-7b) 3.95–3.87 (m, 2H, CH2-9), 2.25 (s, 3H,
Me, Ac), 2.10 (s, 3H, Me, Ac); 13C NMR (75 MHz, CDCl3) d 181.8
(CO-2), 170.7, 167.9, 167.9 (2 ꢂ CO-Ac, CO-8), 141.9 (C-3), 133.3,
133.5 (C-4, C-10), 116.8 (C-11) 98.2 (C-1), 68.3, 68.3 (C-5, C-7),
64.3 (C-6), 41.5 (C-9), 20.8, 20.4 (2 ꢂ Me, Ac).
4.1.6.4. (N-Dodecylcarbamoyl)methyl 3,6-di-O-acetyl-2,4-dide-
oxy-2-C-[(E)-(ethoxycarbonyl)methylene]-a-D-glycero-hex-3-
enopyranoside (24). Wittig olefination of the 3-enopyrano-
sid-2-ulose 15 (40 mg, 0.09 mmol) according to general procedure,
was completed within 1 h. The title compound was obtained as a
white solid (25 mg, 54%) after purification by column chromatog-
raphy (diethyl ether/hexane, 4:1 to diethyl ether). Rf = 0.43
Data for 21: Rf = 0.24 (EtOAc/pentane, 2:3); mp 101–103 °C;
½
a 2D0
ꢁ
= +50 (c 0.7, CH2Cl2); 1H NMR (400 MHz, CDCl3) d 7.11 (t,
1H, NH), 6.39 (s, 1H, H-1), 5.95 (dd, 1H, H-4, J2 ,4 = 0.8, J4,5 = 2.0),
5.91 (br d, 1H, H-20), 5.89–5.80 (m, 1H, H-10), 5.19 (dq, 1H, H-
11a, J11a,11b = J9a,11a = J9b,11a = 1.5, J10,11a = 17.1), 5.11 (dq, 1H, H-
11b, J9a,11b = J9b,11b = J11a,11b, J10,11b = 10.3), 4.72 (ddd, 1H, H-5),
4.40–4.30 (m, 2H, H-6a, H-7a, J5,6a = 5.8, J6a,6b = 11.8, J7a,7b = 15.6),
4.27 (d, part B of AB system, 1H, H-7b), 4.23–4.15 (m, 2H, H-6b,
CH2-Et, J5,6a = 4.3, JEt = 7.1), 3.97–3.91 (m, 2H, CH2-9), 2.27 (s, 3H,
Me, Ac), 2.10 (s, 3H, Me, Ac), 1.29 (t, 3H, CH3-Et); 13C NMR
(100 MHz, CDCl3) d 170.9, 168.9, 168.0 (2 ꢂ CO-Ac, CO-8), 165.4
(CO), 142.1, 140.3 (C-2, C-3), 134.2 (C-10), 121.4 (C-4), 116.4 (C-
11), 114.3 (C-20), 94.2 (C-1), 67.1, 66.7 (C-5, C-7), 64.9 (C-6), 61.2
(CH2-Et), 41.5 (C-9), 21.0, 20.9 (2 ꢂ Me, Ac), 14.3 (CH3-Et); HRMS:
calcd for C19H25NO9 [M+Na]+ 434.1427, found 434.1426.
(EtOAc/pentane, 2:3);
½
a 2D0 = +26 (c 0.5, CH2Cl2); 1H NMR
ꢁ
0
(400 MHz, CDCl3) d 7.04 (t, 1H, NH), 6.37 (s, 1H, H-1), 5.95 (dd,
1H, H-4, J2 ,4 = 0.8, J4,5 = 2.0), 5.91 (br d, 1H, H-20), 4.71 (ddd, 1H,
0
H-5), 4.37 (dd, part
A of ABX system, H-6a, J5,6a = 5.8,
J6a,6b = 11.6), 4.31 (d, part A of AB system, H-7a, J7a,7b = 15.6),
4.26–4.14 (m, 4H, H-6b, H-7b, CH2-Et, J5,6a = 4.3, JEt = 7.1), 3.32–
3.24 (m, 2H, CH2-9), 2.27 (s, 3H, Me, Ac), 2.10 (s, 3H, Me, Ac),
1.57–1.47 (m, 2H, CH2-10), 1.34–1.20 (m, 21 H, CH3-Et, C9H18),
0.88 (t, 3H, CH3-20, J = 7.1); 13C NMR (100 MHz, CDCl3) d 170.9,
168.9, 168.0 (2 ꢂ CO-Ac, CO-8), 165.4 (CO), 142.1, 140.4 (C-2, C-
3), 121.4 (C-4), 114.3 (C-20), 94.1 (C-1), 67.1, 66.6 (C-5, C-7), 64.9
(C-6), 61.2 (CH2-Et), 39.3 (C-9), 32.1, 29.8, 29.8, 29.5, 29.5, 27.1,
22.8 (C-10–C-19), 20.9, 20.9 (2 ꢂ Me, Ac), 14.3 (CH3-Et), 14.3
(CH3-20); HRMS: calcd for C28H45NO9 [M+Na]+ 562.2992, found
562.2996.
4.1.6.2. (N-Propargylcarbamoyl)methyl 3,6-di-O-acetyl-2,4-
dideoxy-2-C-[(E)-(ethoxycarbonyl)methylene]-a-D-glycero-hex-
3-enopyranoside (22). Wittig olefination of the 3-enopyr-
4.1.7. General procedure for the CuI/Amberlyst A21-catalyzed
cycloaddition of (N-propargylcarbamoyl)methyl glycosides
with a terminal azide
anosid-2-ulose 13 (28 mg, 0.08 mmol) according to general proce-
dure, was completed within 2.5 h. The title compound was
obtained as a white solid (19 mg, 56%) after purification by column
chromatography (diethyl ether/hexane, 9:1 to diethyl ether).
To
a solution of (N-propargylcarbamoyl)methyl glycoside
(0.17 mmol) in dichloromethane (1.5 mL) was added azide
(0.2 mmol) and CuI/Amberlyst A21 catalyst 0.8 mmol/g (17 mg,
0.08 eq.). The suspension was stirred at room. temp. overnight.
After filtration of the catalyst and evaporation of the solvent, the
crude was purified by column chromatography on silica gel.
Rf = 0.30 (EtOAc/pentane, 2:3); mp 106–108 °C; ½a D20
ꢁ
= +31 (c 0.4,
CH2Cl2); 1H NMR (400 MHz, CDCl3) d 7.34 (t, 1H, NH), 6.38 (s, 1H,
H-1), 5.95 (dd, 1H, H-4, J2 ,4 = 1.0, J4,5 = 2.0), 5.92 (br d, 1H, H-20),
0
4.72 (ddd, 1H, H-5), 4.39–4.31 (m, 2H, H-6a, H-7a, J5,6a = 5.8,
J6a,6b = 11.8, J7a,7b = 15.6), 4.29–4.14 (m, 4H, H-6b, H-7b, CH2-Et,
J5,6a = 4.3, JEt = 7.1), 4.13–4.06 (m, 2H, CH2-9, JH-9,H-11 = 2.5, JH-
9,NH = 5.5), 2.27 (s, 3H, Me, Ac), 2.19 (t, 1H, H-11), 2.10 (s, 3H, Me,
Ac), 1.31 (t, 1H, CH3-Et); 13C NMR (100 MHz, CDCl3) d 170.9,
168.9, 168.0 (2 ꢂ CO-Ac, CO-8), 165.5 (CO), 142.1, 140.2 (C-2, C-
3), 121.4 (C-4), 114.4 (C-20), 94.3 (C-1), 79.6 (C-10), 71.3 (C-11),
67.1, 66.7 (C-5, C-7), 64.9 (C-6), 61.3 (CH2-Et), 28.6 (C-9), 20.9,
20.9 (2 ꢂ Me, Ac), 14.3 (CH3-Et); HRMS: calcd for C19H23NO9
[M+Na]+ 432.1271, found 432.1272.
4.1.7.1.
{[N-(1-Benzyl-1H-1,2,3-triazol-4-yl)methyl]carbam-
-galactopyranoside (25). CuI/
oyl}methyl 3,4,6-tri-O-acetyl-
a-D
Amberlyst A21-catalyzed coupling of (N-propargylcarbamoyl)methyl
glycoside 7 (0.07 g, 0.17 mmol) with benzyl azide according to general
procedure gave the triazole derivative 25 (66 mg, 71%) as a colorless
oil after purification by column chromatography (from EtOAc to
EtOAc/methanol, 9:1). Rf = 0.22 (EtOAc); ½a D20
ꢁ
= +92 (c 1.3, CH2Cl2); H
NMR (400 MHz, CDCl3) d 8.29 (br s, 1H, NH), 7.50 (br s, 1H, H-11),
7.38–7.31 (m, 3H, Ph), 7.26–7.21 (m, 2H, Ph), 5.44 (s, 2H, CH2Ph),
5.39 (br d, 1H, H-4), 5.21 (dd, 1H, H-3, J2,3 = 10.6, J3,4 = 3.3), 4.92 (d,
4.1.6.3. (N-Benzylcarbamoyl)methyl 3,6-di-O-acetyl-2,4-dide-
oxy-2-C-[(E)-(ethoxycarbonyl)methylene]-
a
-D
-glycero-hex-3-
1H, H-1, J1,2 = 3.8), 4.55 (br d, part
A of ABX system, H-9a,
enopyranoside (23). Wittig olefination of the 3-enopyrano-
J9a,9b = 12.8), 4.32 (br d, part B of ABX system, H-9b), 4.25–4.18 (m,

N. M. Xavier et al. / Bioorg. Med. Chem. 19 (2011) 926–938
935
2H, H-5, H-7a), 4.10–4.00 (m, 4H, H-2, H-6a, H-6b, H-7b), 2.10 (s, 3H,
Me, Ac), 2.01 (s, 3H, Me, Ac), 1.97 (s, 3H, Me, Ac); 13C NMR (100 MHz,
CDCl3) d 170.7, 170.6, 170.2, 169.5 (3 ꢂ CO-Ac, CO-8), 134.2 (Cq, Ph),
129.3, 129.0, 128.3 (CH, Ph), 100.0 (C-1), 70.1 (C-3), 68.1, 67.6, 67.3
(C-4, C-5, C-7), 66.5 (C-2), 61.8 (C-6), 54.5 (C-10), 34.1 (C-9), 20.9,
20.8, 20.7 (3 ꢂ Me, Ac); HRMS: calcd for C24H30N4O10 [M+Na]+
557.1860, found 557.1861.
(C-9), 21.0 20.9, 20.8 (3 ꢂ Me, Ac); HRMS: calcd for C24H30N4O10
[M+Na]+ 557.1860, found 557.1859.
4.1.7.4.
oyl}methyl 3,4,6-tri-O-acetyl-b-
(1-benzyl-5-iodo-1,2,3-triazol-4-yl)methyl]carbamoyl}methyl 3,4,6-
tri-O-acetyl-b- -glucopyranoside (30). CuI/Amberlyst A21-
{[N-(1-Benzyl-1H-1,2,3-triazol-4-yl)methyl]carbam-
D-glucopyranoside (29) and {[N-
D
catalyzed coupling of (N-propargylcarbamoyl)methyl glycoside
718b (51 mg, 0.13 mmol) with benzyl azide according to general
procedure gave the triazole 29 (52 mg, 77%) as a white solid and
its 5-iodo triazole derivative 30 (3 mg, 4%) a colorless oil after puri-
fication by column chromatography (from EtOAc to EtOAc/MeOH,
9:1).
4.1.7.2. ({N-[1-(Hex-5-en-1-yl)-1H-1,2,3-triazol-4-yl]methyl}car-
bamoyl) methyl 3,4,6-tri-O-acetyl-
and ({N-[1-(hex-5-en-1-yl)-5-iodo-1,2,3-triazol-4-yl]methyl} carbam-
oyl)methyl 3,4,6-tri-O-acetyl- -galactopyranoside (27). CuI/
a-D-galactopyranoside (26)
a-D
Amberlyst A21-catalyzed coupling of (N-propargylcarba-
moyl)methyl glycoside 10 (0.099 g, 0.25 mmol) with 5-hexenyl
azide according to general procedure gave the triazole 26 (96 mg,
74%) and its 5-iodo triazole derivative 27 (7 mg, 4%) as colorless
oils after purification by column chromatography (from EtOAc to
EtOAc/methanol, 9:1).
Data for 29: Rf = 0.24 (EtOAc); mp 147–149 °C; ½a D20
ꢁ
= +2 (c 0.5,
CH2Cl2); 1H NMR (400 MHz, CDCl3) d 8.01 (t, 1H, NH, J = 5.8), 7.47
(br s, 1H, H-11), 7.37–7.32 (m, 3H, Ph), 7.26–7.22 (m, 2H, Ph),
5.48 (d, 1H, OH, J = 5.8), 5.45 (br s, 2H, CH2Ph), 5.14 (d, 1H, H-3,
J2,3 = J3,4 = 9.6), 4.99 (t, 1H, H-4, J3,4 = J4,5), 4.51–4.37 (m, 3H, H-1,
CH2-9, J1,2 = 7.8, J9a,9b = 15.4), 4.34 (d, part A of AB system, 1H, H-
7a, J7a,7b = 15.6), 4.25 (dd, part A of ABX system, 1H, H-6a,
J5,6a = 4.8, J6a,6b = 12.3), 4.12 (d, part B of AB system, 1H, H-7b),
4.07 (dd, part B of ABX system, 1H, H-6b, J5,6b = 2.0), 3.69 (ddd,
1H, H-5), 3.61 (ddd, 1H, 2H), 2.05 (s, 3H, Me, Ac), 2.01 (s, 3H, Me,
Ac), 2.00 (s, 3H, Me, Ac); 13C NMR (100 MHz, CDCl3) d 170.9,
170.8, 169.7, 169.6 (3 ꢂ CO-Ac, CO-8), 145.5 (C-10), 134.2 (Cq,
Ph), 129.3, 129.0, 128.3 (CH, Ph), 122.6 (C-11), 103.1 (C-1), 74.9
(C-3), 72.1 (C-5), 71.8 (C-2), 68.8 (C-7), 68.3 (C-4), 62.0 (C-6),
54.4 (C-10), 34.1 (C-9), 20.9, 20.8, 20.7 (3 ꢂ Me, Ac); HRMS: calcd
for C24H30N4O10 [M+Na]+ 557.1860, found 557.1861.
Data for 26: Rf = 0.22 (EtOAc); ½a D20
ꢁ
= +71 (c 0.8, CH2Cl2); 1H
NMR (400 MHz, CDCl3) d 8.33 (t, 1H, NH), 7.55 (s, 1H, H-11),
5.78–5.66 (m, 1H, H-50), 5.38 (br d, 1H, H-4, J3,4 = 3.3, J4,5 = 1.0),
5.21 (dd, 1H, H-3, J2,3 = 10.6), 5.05 (br d, 1H, OH), 5.01–4.92 (m,
2H, H-60a, H-60b), 4.91 (d, 1H, H-1, J1,2 = 3.5), 4.58 (dd, part A of
ABX system, 1H, H-9a, J9a,NH = 6.3, J9a,9b = 15.4), 4.38–4.18 (m, 5H,
H-5, H-7a, H-9b, H-10a, H-10b, J7a,7b = 15.6), 4.10–4.00 (m, 4H, H-
2, H-6a, H-6b, H-7b), 2.12–2.03 (m, 5H, CH2-40, Me, Ac), 2.01 (s,
3H, Me, Ac), 1.97 (s, 3H, Me, Ac), 1.91–1.82 (m, 2H, CH2-20), 1.44–
1.34 (m, 2H, CH2-30); 13C NMR (100 MHz, CDCl3) d 170.7, 170.5,
170.2, 169.5 (3 ꢂ CO-Ac, CO-8), 144.6 (C-10), 137.7 (C-50), 122.4
(C-11), 115.5 (C-60), 100.0 (C-1), 70.1 (C-3), 68.1 (C-4), 67.6, (C-
7), 67.2 (C-5), 66.5 (C-2), 61.8 (C-6), 50.4 (C-10), 34.0 (C-9), 33.0
(C-40), 29.5 (C-20), 25.7 (C-30), 20.9, 20.8, 20.7 (3 ꢂ Me, Ac); HRMS:
calcd for C23H34N4O10 [M+Na]+ 549.2173, found 549.2174.
Data for 30: Rf = 0.41 (EtOAc); 1H NMR (400 MHz, CDCl3) d 7.81
(br t, 1H, NH), 7.40–7.32 (m, 3H, Ph), 7.30–7.23 (m, Ph), 5.58 (br s,
2H, CH2Ph), 5.12 (d, 1H, H-3, J2,3 = J3,4 = 9.6), 5.03 (t, 1H, H-4,
J3,4 = J4,5), 4.61 (dd, part A of ABX system, 1H, H-9a, J9a,NH = 5.5,
J9a,9b = 15.4), 4.49–4.35 (m, 3H, H-1, H-9b, H-7a J1,2 = 8.1,
J7a,7b = 16.1, J9a,9b = 15.4,), 4.29–4.18 (m, 1H, H-6a, H-7b, J5,6a = 4.8,
J6a,6b = 12.3), 4.09 (dd, part B of ABX system, 1H, H-6b, J5,6b = 2.0),
3.68 (ddd, 1H, H-5), 3.62 (dd, 1H, 2H), 2.09 (s, 3H, Me, Ac), 2.07
(s, 3H, Me, Ac), 2.03 (s, 3H, Me, Ac); 13C NMR (100 MHz, CDCl3) d
171.1, 170.8, 169.7, 169.4 (3 ꢂ CO-Ac, CO-8), 133.9 (Cq, Ph),
129.1, 128.8, 128.1 (CH, Ph), 103.1 (C-1), 75.3 (C-3), 72.3 (C-5),
72.1 (C-2), 68.7 (C-7), 68.1 (C-4), 62.0 (C-6), 54.6 (C-10), 34.9 (C-
9), 21.0, 20.9, 20.8 (3 ꢂ Me, Ac); HRMS: calcd for C24H29IN4O10
[M+Na]+ 683.0827, found 683.0827.
Data for 27: Rf = 0.48 (EtOAc); 1H NMR (400 MHz, CDCl3) d 8.12
(t, 1H, NH), 5.91–5.66 (m, 1H, H-50), 5.43 (dd, 1H, H-4, J3,4 = 3.3,
J4,5 = 1.0), 5.26 (dd, 1H, H-3, J2,3 = 10.5), 5.09–4.96 (m, 2H, H-60a,
H-60b), 4.93 (d, 1H, H-1, J1,2 = 3.7), 4.79 (dd, part A of ABX system,
1H, H-9a, J9a,NH = 7.6, J9a,9b = 15.9), 4.44 (br s, 1H, OH), 4.40–4.22
(m, 5H, H-5, H-7a, H-9b, CH2-10, J7a,7b = 15.6), 4.21–4.05 (m, 4H,
H-2, H-6a, H-6b, H-7b), 2.17–2.06 (m, 5H, CH2-40, Me, Ac), 2.05
(br s, 6H, 2 ꢂ Me, Ac), 1.97 (s, 3H, Me, Ac), 1.98–1.85 (m, 2H,
CH2-20), 1.52–1.38 (m, 2H, CH2-30); 13C NMR (100 MHz, CDCl3) d
170.8, 170.6, 170.3, 169.3 (3 ꢂ CO-Ac, CO-8), 144.4 (C-10), 137.8
(C-50), 115.6 (C-60), 100.0 (C-1), 69.9 (C-3), 68.2 (C-4), 67.7, (C-7),
67.4 (C-5), 66.7 (C-2), 61.8 (C-6), 51.0 (C-10), 34.7 (C-9), 33.1 (C-
40), 29.3 (C-20), 25.7 (C-30), 21.0, 20.8, 20.8 (3 ꢂ Me, Ac); HRMS:
calcd for C23H34IN4O10 [M+Na]+ 675.1139, found 675.1140.
4.1.7.5.
yl]methyl}carbamoyl)methyl 2,3,4,6-tetra-O-allyl-
pyranoside (31) and ({N-Allyl, N-[1-(hex-5-en-1-yl)-1H-1,2,3-
triazol-4-yl]methyl}carbamoyl)methyl 2,4,6-tri-O-allyl-
galactopyranoside (32). To solution of compound 26
({N-Allyl,
N-[1-(hex-5-en-1-yl)-1H-1,2,3-triazol-4-
a-D-galacto-
a-D-
4.1.7.3.
{[N-(1-Benzyl-1H-1,2,3-triazol-4-yl)methyl]carbam-
-glucopyranoside (28). CuI/
a
oyl}methyl 3,4,6-tri-O-acetyl-
a-D
(44 mg, 0.08 mmol) in dry DMF (1.2 mL) was added NaH
(0.42 mmol, 60%, 17 mg). After a few minutes, allyl bromide
(0.42 mmol, 36 lL) was added and the mixture was stirred at
50 °C for 1 h. Water was added (8 mL) and the aqueous phase
was extracted with EtOAc (3 ꢂ 3 mL). The combined organic layers
were washed with water and dried with Na2SO4. After filtration
and evaporation of the solvent, the residue was purified by column
chromatography (from EtOAc/pentane, 7:3 to EtOAc) to afford 31
(16 mg, 32%) and 32 (9 mg, 20%) as colorless oils.
Amberlyst A21-catalyzed coupling of (N-propargylcarba-
moyl)methyl glycoside 418a (0.115 g, 0.29 mmol) with benzyl azide
according to general procedure gave the triazole derivative 28
(92 mg, 60%) as a colorless oil after purification by column chroma-
tography (from EtOAc to EtOAc/methanol, 9:1); Rf = 0.21 (EtOAc);
½
a 2D0 = +64 (c 0.9, CH2Cl2); 1H NMR (400 MHz, CDCl3) d 8.24 (br t,
ꢁ
1H, NH), 7.45 (br s, 1H, H-11), 7.40–7.33 (m, 3H, Ph), 7.29–7.23
(m, 2H, Ph), 5.47 (s, 2H, CH2Ph), 5.34 (br d, 1H, H-3,
J2,3 = J3,4 = 10.0), 5.02 (t, 1H, H-4, J3,4 = J4,5), 4.86 (d, 1H, H-1,
J1,2 = 3.8), 4.69 (dd, 1H, H-9a, J9a,NH = 7.3, J9a,9b = 15.5), 4.35–4.19
(m, 3H, H-6a, H-7a, H-9b), 4.09–4.00 (m, 3H, H-5, H-6b, H-7b),
3.84 (dd, 1H, H-2), 2.08 (s, 3H, Me, Ac), 2.06 (s, 3H, Me, Ac), 2.02
(s, 3H, Me, Ac); 13C NMR (100 MHz, CDCl3) d 171.2, 170.8, 169.8,
169.5 (3 ꢂ CO-Ac, CO-8), 145.0 (C-10), 134.2 (Cq, Ph), 129.3,
129.1, 128.3 (CH, Ph), 122.1 (C-11), 99.5 (C-1), 72.8 (C-3), 70.3
(C-2), 68.3, 68.2, 67.7 (C-4, C-5, C-7), 62.0 (C-6), 54.5 (C-10), 34.0
Data for 31: Rf = 0.56 (EtOAc/pentane, 7:3); ½a D20
ꢁ
= +19 (c 1.2,
CH2Cl2); 1H NMR (400 MHz, CDCl3) d 7.58 (s, 1H, H-11), 6.02–
5.67 (m, 6H, 5 ꢂ CH allylic, H-50), 5.37–5.08 (m, 11H, H-1, 5 ꢂ @CH2
allylic), 5.06–4.93 (m, 2H, @CH2-60), 4.60 (d, part A of AB system, H-
9a, J9a,9b = 14.9), 4.53 (d, part A of AB system, H-9b), 4.44–3.83 (m,
16H, 5 ꢂ CH2 allylic, H-2, H-5, CH2-7, CH2-10, J1,2 = 3.7), 3.81 (br d,
1H, H-4, J3,4 = 3.1), 3.75 (dd, 1H, H-3, J3,4 = 2.9, J2,3 = 10.1), 3.62–
3.45 (m, 2H, CH2-6, J5,6a = 6.4, J5,6b = 6.4, J6a,6b = 9.3), 2.14–2.04 (m,

936
N. M. Xavier et al. / Bioorg. Med. Chem. 19 (2011) 926–938
2H, CH2-40), 1.96–1.82 (m, 2H, CH2-20), 1.48–1.35 (m, 2H, CH2-30);
13C NMR (100 MHz, CDCl3) d 168.8 (CO-8), 144.2 (C-10), 137.9,
135.5 135.3, 135.3, 134.6, 132.6 (C-50, 5 ꢂ CH allylic), 123.4 (C-
11), 117.5, 117.3, 117.2, 117.0, 116.3 (5 ꢂ @CH2 allylic) 115.5 (C-
60), 97.2 (C-1), 78.0 (C-3), 76.0 (C-2), 75.1 (C-4), 74.2 (CH2 allylic-
4), 72.5 (CH2 allylic-6), 72.1, 72.1 (CH2 allylic-2, CH2 allylic-3),
70.0 (C-5), 69.0 (C-6), 64.5 (C-7), 50.3 (C-10), 49.5 (N-CH2 allylic),
41.0 (C-9), 33.1 (C-40), 29.7 (C-20), 25.8 (C-30); HRMS: calcd for
(CO), 145.4 (C-10), 142.0, 140.1 (C-2, C-3), 134.7 (Cq, Ph), 129.3,
128.9, 128.2 (CH, Ph), 122.5 (C-11), 121.3 (C-4), 114.4 (C-20), 94.3
(C-1), 67.1, 66.8 (C-5, C-7), 68.7 (C-7), 64.9 (C-6), 61.3 (CH2-Et),
54.3 (C-10), 34.7 (C-9), 21.0, 20.9 (2 ꢂ Me, Ac), 14.3 (CH3-Et);
HRMS: calcd for C26H30N4O9 [M+Na]+ 565.1910, found 565.1914.
4.1.8. General procedure for deacetylation of compounds 25, 26,
28, and 29
A solution of 2,3,4,6-tetra-O-acetylated glycoside (0.03 mmol)
in CH3OH/H2O/NEt3 (8:1:1, 2 mL) was stirred overnight at 40 °C.
After evaporation of the solvents under vacuum, the residue was
purified by column chromatography.
C
32H48N4O7 [M+Na]+ 623.3421, found 623.3423.
Data for 32: Rf = 0.23 (EtOAc/pentane, 7:3); ½a D20
ꢁ
= +32 (c 0.7,
CH2Cl2); 1H NMR (400 MHz, CDCl3) d 7.58 (s, 1H, H-11), 6.04–
5.58 (m, 5H, 4 ꢂ CH allylic, H-50), 5.35–5.11 (m, 9H, H-1, 4 ꢂ @CH2
allylic), 5.07–4.94 (m, 2H, @CH2-60), 4.62 (d, part A of AB system, H-
9a, J9a,9b = 15.1), 4.53 (d, part A of AB system, H-9b), 4.40–3.83 (m,
14H, 4 ꢂ CH2 allylic, H-3, H-5, CH2-7, CH2-10), 3.82 (br d, 1H, H-4,
J3,4 = 3.1), 3.73 (dd, 1H, H-2, J1,2 = 3.7, J2,3 = 10.3), 3.62–3.50 (m,
2H, CH2-6, J5,6a = 6.5, J5,6b = 6.5, J6a,6b = 9.3), 2.17–2.02 (m, 2H,
CH2-40), 1.99–1.82 (m, 2H, CH2-20), 1.52–1.34 (m, 2H, CH2-30); 13C
NMR (100 MHz, CDCl3) d 168.8 (CO-8), 144.1 (C-10), 137.9, 135.1,
134.8, 134.5, 132.4 (C-50, 4 ꢂ CH allylic), 123.4 (C-11), 117.9,
117.6, 117.4, 117.3 (4 ꢂ @CH2 allylic) 115.5 (C-60), 96.1 (C-1),
76.5 (C-4, C-2), 74.5 (CH2 allylic-4), 72.5 (CH2 allylic-6), 71.3 (CH2
allylic-2), 69.9, 69.9 (C-3, C-5), 69.0 (C-6), 64.1 (C-7), 50.4 (C-10),
49.5 (N-CH2 allylic), 41.0 (C-9), 33.1 (C-40), 29.7 (C-20), 25.8 (C-
30); HRMS: calcd for C29H44N4O7 [M+Na]+ 583.3108, found
583.3105.
4.1.8.1. {[N-(1-Benzyl-1H-1,2,3-triazol-4-yl)methyl]carbamoyl}
methyl-a-
D-galactopyranoside (35).
Deacetylation (CH3OH/
H2O/NEt3) of glycoside 25 (19 mg, 0.036 mmol), according to gen-
eral procedure afforded compound 35 (12 mg, 82%) as a colorless
oil after purification by column chromatography (EtOAc/MeOH,
4:1). Rf = 0.23 (EtOAc/methanol, 4:1); ½a D20
ꢁ
= +61 (c 1, MeOH/
CH2Cl2, 1:1); 1H NMR (400 MHz, MeOD) d 7.87 (br s, 1H, H-11),
7.42–7.28 (m, 3H, Ph), 5.57 (s, 2H, CH2Ph), 4.85 (d, 1H, H-1,
J1,2 = 3.5), 4.51 (s, 2H, CH2-9), 4.21 (d, part A of AB system, H-7a,
J7a,7b = 15.9), 4.03 (d, part B of AB system, H-7b), 3.88 (br d, 1H,
H-4, J3,4 = 3.3), 3.84–3.63 (m, 5H, H-2, H-3, H-5, H-6a, H-6b,
J2,3 = 10.3, J5,6b = 5.0, J6a,6b = 11.3); 13C NMR (100 MHz, MeOD) d
172.3 (CO-8), 136.7 (Cq, Ph), 130.0, 129.6, 129.2 (CH, Ph), 124.3
(C-11), 101.2 (C-1), 73.1 (C-3), 71.3 (C-5), 71.0 (C-4), 70.0 (C-2),
67.9 (C-7), 62.8 (C-6), 55.0 (C-10), 35.2 (C-9); HRMS: calcd for
4.1.7.6. {[N-(1-Benzyl-1H-1,2,3-triazol-4-yl)methyl]carbamoyl}
methyl 3,6-di-O-acetyl-4-deoxy-
a
-D
-glycero-hex-3-enopyrano-
C
18H24N4O7 [M+Na]+ 431.1543, found 431.1544.
sid-2-ulose (33). DMSO/Ac2O oxidation of compound 28
(88 mg, 0.17 mmol) according to general procedure gave the corre-
sponding 3-enopyranosid-2-ulose 33 (47 mg, 60%) as a colorless oil
after purification by column chromatography (from EtOAc/pen-
4.1.8.2.
carbamoyl)methyl-
({N-[1-(Hex-5-en-1-yl)-1H-1,2,3-triazol-4-yl]methyl}
-galactopyranoside (36). Deacetyla-
a-D
tion (CH3OH/H2O/NEt3) of glycoside 26 (17 mg, 0.032 mmol),
according to general procedure afforded compound 36 (12 mg,
95%) as a colorless oil after purification by column chromatography
tane, 4:1 to EtOAc). Rf = 0.40 (EtOAc); ½a D20
ꢁ
= +6 (c 0.4, CH2Cl2); 1H
NMR (300 MHz, CDCl3) d 7.47 (br s, 1H, H-11), 7.40–7.33 (m, 3H,
Ph), 7.29–7.23 (m, 2H, Ph), 7.04 (br t, 1H, NH), 6.64 (d, 1H, H-4,
J4,5 = 1.7), 5.49 (br s, 2H, CH2Ph), 5.02 (s, 1H, H-1), 4.95 (td, 1H,
H-5), 4.57–4.51 (m, 2H, CH2-9) 4.41 (dd, part A of ABX system,
1H, H-6a, J5,6a = 5.3, J6a,6b = 11.7), 4.31 (d, part A of AB system, 1H,
H-7a, J7a,7b = 15.1), 4.25–4.14 (m, 2H, H-6b, H-7b, J5,6b = 4.5), 2.25
(s, 3H, Me, Ac), 2.10 (s, 3H, Me, Ac); 13C NMR (100 MHz, CDCl3) d
181.6 (CO), 170.7, 168.1, 167.9 (2 ꢂ CO-Ac, CO-8), 141.8 (C-4),
134.6 (Cq, Ph), 133.2 (C-3), 129.2, 128.9, 128.2 (CH, Ph), 98.1 (C-
1), 68.4, 68.3 (C-5, C-7), 64.3 (C-6), 54.3 (C-10), 34.7 (C-9), 20.8,
(EtOAc/MeOH, 4:1). ½a D20
ꢁ
= +33 (c 0.6, MeOH/CH2Cl2, 1:1); Rf = 0.32
(EtOAc/methanol, 5:1); 1H NMR (400 MHz, MeOD) d 7.88 (br s, 1H,
H-11), 5.88–5.71 (m, 1H, H-50), 5.07–4.91 (m, 2H, H-60a, H-60b),
4.86 (d, 1H, H-1), 4.52 (s, 2H, CH2-9), 4.39 (t, 2H, CH2-10), 4.24 (d,
part A of AB system, H-7a, J7a,7b = 15.5), 4.05 (d, part B of AB sys-
tem, H-7b), 3.89 (br d, 1H, H-4, J3,4 = 3.1, J4,5 = 1.0), 3.85–3.64 (m,
5H, H-2, H-3, H-5, H-6a, H-6b, J1,2 = 3.1, J2,3 = 10.1, J5,6b = 5.3,
J6a,6b = 11.1), 2.14–2.06 (m, 5H, CH2-40), 1.98–1.84 (m, 2H, CH2-
20), 1.46–1.35 (m, 2H, CH2-30); 13C NMR (100 MHz, MeOD) d
172.3 (CO-8), 146.0 (C-10), 139.2 (C-50), 124.2 (C-11), 115.5 (C-
60), 101.3 (C-1), 73.1 (C-3), 71.3 (C-5), 71.0 (C-4), 70.0 (C-2), 68.0
(C-7), 62.8 (C-6), 51.2 (C-10), 35.2 (C-9), 34.1 (C-40), 30.7 (C-20),
26.8 (C-30); HRMS: calcd for C17H28N4O7 [M+Na]+ 423.1856, found
423.1858.
20.4 (2 ꢂ Me, Ac); HRMS: calcd for
C
22H24N4O8 [M+Na]+
495.1492, found 495.1493.
4.1.7.7. {[N-(1-Benzyl-1H-1,2,3-triazol-4-yl)methyl]carbamoyl}
methyl 3,6-di-O-acetyl-2,4-dideoxy-2-C-[(E)-(ethoxycarbonyl)
methylene]-
a
-D
-glycero-hex-3-enopyranoside
(34).
CuI/
Amberlyst A21-catalyzed coupling of (N-propargylcarba-
moyl)methyl glycoside 22 (20 mg, 0.05 mmol) with benzyl azide
according to general procedure gave the triazole derivative 34
(23 mg, 87%) as a white solid after purification by column chroma-
tography (from EtOAc/pentane, 7:3 to EtOAc). Rf = 0.43 (EtOAc);
4.1.8.3. {[N-(1-Benzyl-1H-1,2,3-triazol-4-yl)methyl]carbamoyl}
methyl-a-
D-glucopyranoside (37).
Deacetylation (CH3OH/
H2O/NEt3) of glycoside 28 (17 mg, 0.032 mmol), according to gen-
eral procedure afforded compound 37 (12 mg, 92%) as a colorless
oil after purification by column chromatography (EtOAc/MeOH,
mp 172–174 °C; ½a D20
ꢁ
= +10 (c 0.2, CH2Cl2); 1H NMR (400 MHz,
4:1). Rf = 0.24 (EtOAc/methanol, 4:1); ½a D20
ꢁ
= +57 (c 1.1, MeOH/
CDCl3) d 7.57 (br t, 1H, NH), 7.48 (s, 1H, H-11), 7.39–7.32 (m, 3H,
CH2Cl2, 1:1); 1H NMR (400 MHz, MeOD) d 7.88 (br s, 1H, H-11),
7.41–7.29 (m, 3H, Ph), 5.57 (s, 2H, CH2Ph), 4.81 (d, 1H, H-1,
J1,2 = 3.8), 4.51 (s, 2H, CH2-9), 4.22 (d, part A of AB system, H-7a,
J7a,7b = 15.6), 4.03 (d, part B of AB system, H-7b), 3.80 (dd, part A
of ABX system, H-6a, J5,6a = 2.2, J6a,6b = 11.8), 3.68–3.61 (m, 2H, H-
3, H-6b), 3.54 (ddd, 1H, H-5, J4,5 = 9.8, J5,6b = 5.8), 3.43 (dd, 1H, H-
2, J2,3 = 9.6), 3.33 (dd, 1H, H-4, J3,4 = 9.1); 13C NMR (100 MHz,
MeOD) d 172.2 (CO-8), 146.3 (C-10), 136.7 (Cq, Ph), 130.0, 129.6,
129.2 (CH, Ph), 124.3 (C-11), 101.0 (C-1), 74.9 (C-3), 74.4 (C-5),
73.3 (C-2), 71.6 (C-4), 67.8 (C-7), 62.5 (C-6), 55.0 (C-10), 35.2 (C-
Ph), 7.29–7.23 (m, 2H, Ph), 6.36 (s, 1H, H-1), 5.93 (dd, 1H, H-4,
J2 ,4 = 0.8, J4,5 = 2.0), 5.89 (br d, 1H, H-20), 5.48 (s, 2H, CH2Ph), 4.69
0
(ddd, 1H, H-5), 4.60 (dd, part A of ABX system, 1H, H-9a,
J9a,NH = 6.3, J9a,9b = 15.4), 4.50 (dd, part B of ABX system, 1H, H-
9b, J9a,NH = 6.0), 4.37–4.27 (m, 2H, H-6a, H-7a, J5,6a = 5.8,
J6a,6b = 11.6, J7a,7b = 15.6), 4.24 (d, part B of AB system, 1H, H-7b),
4.18–4.09 (m, 3H, H-6b, CH2-Et, J5,6b = 4.0, JEt = 7.1), 2.26 (s, 3H,
Me, Ac-3), 2.09 (s, 3H, Me, Ac-6), 1.25 (t, 1H, CH3-Et); 13C NMR
(100 MHz, CDCl3) d 170.9, 169.2, 168.0 (2 ꢂ CO-Ac, CO-8), 165.4

N. M. Xavier et al. / Bioorg. Med. Chem. 19 (2011) 926–938
937
9); HRMS: calcd for C18H24N4O7 [M+Na]+ 431.1543, found
431.1541.
removed, cells were washed twice to remove traces of medium and
un-metabolized MTT, and DMSO (100 L) was added to each well.
l
Solubilization of formazan crystals was performed by agitation in a
96-well plate shaker for 20 min at room temperature. Absorbance
of each well was quantified at 550 nm using 620 nm as reference
wavelength on a scanning multiwall spectrophotometer (auto-
mated plate reader).
4.1.8.4.
oyl}methyl-b-
{[N-(1-Benzyl-1H-1,2,3-triazol-4-yl)methyl]carbam-
-glucopyranoside (38). Deacetylation
D
(CH3OH/H2O/NEt3) of glycoside 29 (16 mg, 0.03 mmol), according
to general procedure afforded compound 38 (11 mg, 90%) as a
white solid after purification by column chromatography (EtOAc/
MeOH, 4:1). Rf = 0.24 (EtOAc/methanol, 4:1); mp 154–155 °C;
References and notes
½
a 2D0
ꢁ
= ꢀ11 (c 0.8, MeOH/CH2Cl2, 1:1); 1H NMR (400 MHz, MeOD) d
1. Amslinger, S. ChemMedChem 2010, 5, 351.
7.87 (br s, 1H, H-11), 7.41–7.29 (m, 5H, Ph), 5.57 (s, 2H, CH2Ph),
4.53 (d, part A of AB system, H-9a, J7a,7b = 15.4), 4.48 (d, part B of
AB system, H-9b), 4.35–4.28 (m, 2H, H-1, H-7a, J1,2 = 7.8,
J7a,7b = 15.9), 4.17 (d, part B of AB system, H-7b), 3.83 (dd, part A of
ABX system, H-6a, J5,6a = 1.8, J6a,6b = 12.1), 3.65 (dd, partA ofABXsys-
tem, H-6b, J5,6b = 5.3) 3.89–3.21 (m, 4H, H-2, H-3, H-4, H-5); 13C NMR
(100 MHz, MeOD) d 172.4 (CO-8), 136.7 (Cq, Ph), 130.0, 129.6, 129.2
(CH, Ph), 124.3 (C-11), 104.7 (C-1), 78.2 (C-5), 77.8 (C-3), 74.9 (C-2),
71.4 (C-4), 69.5 (C-7), 62.5 (C-6), 55.0 (C-10), 35.2 (C-9); HRMS: calcd
for C18H24N4O7 [M+Na]+ 431.1543, found 431.1543.
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monocytogenes, S. enteritidis, and S. aureus) and actidione and
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£ P 26 mm, +++++; strong activity, 22 mm 6 £ < 26 mm, ++++;
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